1. Evaluate The Dopamine Hypothesis
The key function of antipsychotic drugs as recognised by various researchers, is the significant
interference with brain dopamine function. This is underpinned by the hypothesis that symptoms of
schizophrenia are produced from increased activity of the neurotransmitter dopamine. This essay,
therefore discusses and examines the function and mode of action of these antipsychotics drugs with
a view to critically identifying whether schizophrenia is a disorder of dopamine function.
Dopamine Hypothesis
The dopamine hypothesis of schizophrenia as highlighted by Stone et al 2007 is seen as the principal
explanatory model of antipsychotic drug action. The formulation of dopamine hypothesis was partly
based on neuro pharmacological research that centred ... Show more content on Helpwriting.net ...
However, as highlighted by Videbeck et al (2014), the therapeutic mechanism of action is only
partially understood. Typical antipsychotic drugs such as chlorpromazine, haloperidol, act as
antagonist at dopamine receptors (D2, D3, D4), which are situated in central pathways of the brain.
Brennan & Gamble (2006), highlighted reports supporting the clinical potency of typical
antipsychotics which is determined by the extent to which they block dopamine receptors. This
action of blocking D2 receptors lead to effective treatment of target symptoms of schizophrenia but
induces many extrapyramidal symptoms (EPS) such as Parkinson, acute dystonic reactions,
akathisia, tardive dyskinesia and worsen negative symptoms in some patients. In as much as
blocking the dopamine receptor is acknowledged explanation of the EPS of typical antipsychotic
drugs, some controversy exists in relation to extension of the mechanism to explain the
antipsychotic effect. The core controversy is based on the inability to link the relationship between
EPS and therapeutic effects. Some typical antipsychotic drugs have shown fewer parkinsonian
effects than would have been expected from their clinical efficacy and explanation to this is that
such drugs have in built antiparkinsonian as they have high anticholinergic potency. According to
Crow (1980), considering this explanation makes the relationship between dopamine antagonism
and the therapeutic effectiveness more compelling. Brennan & Gamble (2006), cited Gournay &
Gray (1998), highlighting that about 30% of clients with schizophrenia do not respond to typical
antipsychotics or experience severe EPS, this means that the rest 70% respond to typical
antipsychotic drugs and may experience
... Get more on HelpWriting.net ...
2. Hormones And Behavior Times : Together Forever
Hormones & Behavior Professor Jon–Cavanaugh Amber Park Nov. 11th 2016 Hormones and
Behavior Times: Together Forever...Or Not A study was conducted on monogamous prairie voles to
examine the neural pathway that promotes the development of pair–bonding or close relationships
between different species. Researchers used monogamous prairie voles for the experiment because
they have established partners. Partner preference is a prerequisite for pair bonding but it does not
define a pair bond. Only established when unfamiliar yet potential mates are aggressively rejected.
Previous studies have shown that conduction of dopamine within the nucleus accumbens mediates
both investigative and avoidance behaviors. Previous studies have demonstrated that partner
preferences emerge after 24 hours of mating but not after 6 hours of cohabitation without mating.
The neural pathway occurs within a specific region of the brain called the nucleus accumbens.
Within this brain region, there were two receptor activations that were identified; they were labeled
D1 and D2. The blockade of D2–like receptors prevented partner preferences after mating; D2–like
receptor activation induced this behavior in the absence of mating. It is shown in Figure 1 that the
activation of D2–like receptors within the nucleus accumbens is essential for pair bonding. Doses of
quinpirole, a psychoactive drug that acts as a D2 agonist, were administered within the rostral shell
of the nucleus accumbens. This
... Get more on HelpWriting.net ...
3. The Synthesis Of Apomorphine Was Historically Accomplished...
Introduction: Apomorphine has been used as far back as 2000 BC. In 2000 BC the Mayan's noticed
that the bulb and root of water lilies gave a narcotic feeling, as well as acted as an aphrodisiac and
partial hallucinogen.1 Apomorphine belongs to a class of molecules called aporphines which are
present in water lilies, more specifically in Nymphaea caerulea and Nymphaea ampla.1 While mild
effects were shown in parts of water lilies, scientists wanted to know what exactly caused these
effects. The compounds were isolated and tested to determine that apomorphine was the most active
ingredient. The concentration of apomorphine was so low in the plants that isolation was impractical
so a synthesis was designed to investigate the properties of apomorphine further; leading to
apomorphine being used for Parkinson's disease, erectile dysfunction, and most recently Alzheimer
disease.
Synthesis2: The synthesis of apomorphine was historically accomplished by an acid–catalyzed
rearrangement of morphine. This method typically had low and varying yields: anywhere from 0.6%
to 46% yield. In 2008, a new synthesis was patented that shown yields as high as 55% to 70% yield.
This new synthesis, scheme 1, uses phosphoric acid as the catalyst and phosphorus pentoxide as a
water scavenger–water is the by–product of the reaction and the phosphorus pentoxide irreversibly
binds to the water. The solution would then be heated to 90–100℃ in an inert atmosphere for two
hours.
... Get more on HelpWriting.net ...
4. Understanding the Clinical Management of Pain in Fibromyalgia
Understanding the Clinical Management of Pain in Fibromyalgia
Classical pain presentation in fibromyalgia is often manifested in the muscle on various tender spots
all over the four (4) quadrants of the body. Generally, patients complain of joint pain when in fact
only the surrounding muscles sore. Pain may be accompanied by fatigue, skin sensitivity, tingling
sensations, diarrhea, constipation and sleep disorder. Although, these symptoms are also linked to
other chronic pain syndromes, the health experts came up of a unique tool to discretely differentiate
fibromyalgia from other disease conditions.
Clinicians are very particular to rule out other disorders before diagnosing a patient with
fibromyalgia. As mentioned earlier, signs and symptoms may be similar to other conditions thus
presence of pain alone is not enough to assume that the patient has fibromyalgia for a fact that some
disorders may co–exist with it.
The clinical symptoms of fibromyalgia are quite complex thus focusing on single aspect on pain
care may not efficiently work. Experts categorized treatment and management of fibromyalgia into
three (3)
1. Pain management which focuses to Fibromyalgia.
2. Management of symptoms that may directly or indirectly trigger pain.
3. Management of predisposing conditions caused by fibromyalgia.
Various aspects need must be considered in the management and care of fibromyalgia. For instance,
there are no significant evidences to show that anti–inflammatory drugs diminish
... Get more on HelpWriting.net ...
5. Essay on Caffeine Effects In The Brain
Caffeine Effects In The Brain
Caffeine acts in a multitude of ways in the brain. The most recent studies explore the cooperative
effects of adenosine and dopamine, as well as the increase in calcium in the interstitial fluid and
possible accumulation of cyclic adenosine monophospate. The most popular discussions of earlier
studies of caffeine demonstrate its antagonistic effects on adenosine receptors. While it has been
reported that adenosine receptors are located throughout the brain, the various subtypes can be
found in very specific areas.
Studies have also shown that caffeine reactions in the brain are based on the localization of
adenosine receptors, dopamine receptors, and the amount of caffeine. ... Show more content on
Helpwriting.net ...
(Garrett, 1997; Myers, 1999) According to the
Pacific Nueropsychiatric Institute "caffeine inhibits phosphodiesterase breakdown of cyclie 3',–5'–
adenosine monophosphate. (Pharmacology, caffeine, 2) Again, this occurs only in large quantities
that have yet to be naturally found in vivo. (Myers, 1999) Keep in mind that if cyclic AMP had a
greater than normal concentration in the synaptic cleft, it would continue to breakdown adenosine
which has a depressant effect on functions in the brain. For example, adenosine in the central
nervous system inhibits neurotransmitter release and depresses locomotor activity, however with
higher concentrations of cyclic AMP there is less adenosine so, the effects on the biology of the
brain are an enhanced neurotransmitter release, and stimulated locomotor activity (Garrett, 1997).
Another way caffeine acts on the brain is indirectly through the dopamine receptors. As stated by
Garrett and
Griffiths (1997), "Although caffeine does not bind directly to dopamine receptors a number of
conflicting reports suggest that caffeine can either decrease or increase dopamine release" (p.535).
For example, "Caffeine significantly decreases dihydroxyphenylacetic acid (DOPAC) levels in the
striatum, hypothalamus, and frontal cortex, but increases DOPAC levels in the nucleus accumbens"
(p.535).
Caffeine also is responsible for significant
... Get more on HelpWriting.net ...
6. Stress In The PVT
Stress in the PVT The PVT has shown to have implications in stress processing due to its diverse
population of neurons, holding a variety of functions. People are still discovering more about the
PVT and its roles, but it is important to be able to categorize the neurons directly involved in stress.
To discover more, I worked with c–fos, a protein which is a promoter for previous neuronal activity
for the two restraint–stress experiments. For the first experiment, I used immunohistochemistry to
label neurons expressing c–fos in both control and restraint mice. The raw data shows that with
restraint there is an increase of c–fos expression in the PVT. In addition, the stainings show that
there are two groups of neurons activated during times ... Show more content on Helpwriting.net ...
D2 receptors play a role in psychological functioning, such as: reward, locomotion, and emotion. It
is important to know if these receptors become activated because, D2 receptors are shown to have
implications in stress processing as well, due to their ability to modify the way synapses release and
synthesize dopamine. Moreover, knowing the function of this receptor can give us insight as to how
stress is regulated in the PVT. We began the second restrain–stress experiment with D2–GFP mice
and repeated the same type of restraint–stress behavior as before. The brains were harvested, stained
for c–fos, and confocal images were taken of each animal. After that, I quantified the data and used
imageJ to select c–fos expressing neurons in an unbiased way. After that, I counted the c–fos
positive cells, GFP positive cells, and co–localized cells which expressed both. Once everything was
counted, I calculated the average number of c–fos positive neurons and GFP positive neurons. Next,
I averaged the values and found that the GFP and c–fos expressing cells have a high percentage of
co–localization. For the control mice, there was a 99% co–localization between c–fos and GFP
expressing cells, while there was a 90% co–localization between the c–fos and GFP expressing cells
in restraint mice. The co–localization
... Get more on HelpWriting.net ...
7. Schizophrenia: Types, Symptoms, Medications, Treatment Essay
Schizophrenia is a neurological disorder that affects the cognitive functions of an individual. The
cause of this illness is unknown, but there are several theories of how an individual may acquire
schizophrenia. Because there are many symptoms of the disease and because the symptoms can vary
quite dramatically among several individuals and even within the same individual over time, the
diagnosis of schizophrenia can be quite difficult.
In the United States and Europe, schizophrenia occurs in about 3 to 6 of every 10,000 individuals.
Schizophrenia occurs equally in males and females; however, the age of onset of the disease is
different between the sexes. The primary age of onset in males occurs roughly between the ages of
15 and 25, ... Show more content on Helpwriting.net ...
Since the social causation hypothesis is more narrow and only accounts for the assumption that
schizophrenia results from stress (one hypothesis for the development of schizophrenia), the
downward drift hypothesis seems to better explain the disproportionate numbers of schizophrenics
in the lower socioeconomic classes. Moreover, a number of estimations have claimed that between
one–third and two–thirds of homeless individuals have schizophrenia (1).
However, the theory that social factors may produce the stressors that lead to schizophrenia does
correlate with several key points. Epidemiological studies have shown that a higher proportion of
schizophrenics are found in large cities, particularly in those cities with populations of over one
million people, whereas smaller cities have virtually no incidence of schizophrenia. Also, the
development of schizophrenia in children of a schizophrenic parent or parents appears to be twice as
likely in those residing in large cities as compared to those in smaller communities. Moreover,
schizophrenia occurs in a higher percentage of immigrants that move from a less industrialized area
or nation to a more industrialized area or nation (1). However, other factors may be present that
contribute to the disproportionate localization of schizophrenia in relation to geography which will
be discussed later.
The symptoms of schizophrenia are quite variable in type and
... Get more on HelpWriting.net ...
8. How to Control Huntington’s Disease
Currently, there is no cure for Huntington's disease (HD) and only limited numbers of treatments are
effective in controlling HD symptoms. HD a progressive neurodegenerative disorder characterized
by motor disturbances, psychiatric dysfunctions, and cognitive disabilities. HD is inherited in an
autosomal dominant manner, means that the inheritance of a single copy of the mutant huntingtin
allele containing an expanded CAG repeat region in exon 1 (>36 CAG repeat) causes the disease.
Translation of the mutant allele mRNA yields the mutant huntingtin protein (mHtt) containing an
expanded polyglutamine region near the amino terminus, which favor protein cleavage and
accumulation of the N–terminus in the nucleus. N–terminal huntingtin affects transcription of
subsets of genes. Early in HD progression, levels of the cannabinoid receptor type 1 (CB1) and
dopamine receptor type 2 (D2) are reduced in the medium spiny neurons of the striatum. CB1
receptor is able to activate several signaling pathways through the activation of different G proteins
as well as arrestin–2. Furthermore, compelling anatomical and physiological evidence suggests a
strong interaction between the CB1 and D2 receptors. Given this interaction between CB1 and D2
receptors, drugs that block or activate either receptor will influence convergent signaling pathways.
Typical and atypical antipsychotics, including haloperidol and olanzapine, respectively, are
commonly prescribed to HD patients to control chorea and
... Get more on HelpWriting.net ...
9. Dopamine And Norepinephrine Essay
1. INTRODUCTION
1.1 Overall specific aims
Dopamine (DA) and norepinephrine (NE) are the major catecholamines in the mammalian brain and
play a critical role in the regulation of physiological and behavioral processes (Wise and Rompre
1989; Berridge and Waterhouse 2003; Aston–Jones and Cohen 2005; Aragona et al. 2008;
Weinshenker and Schroeder 2007; Owesson–White et al. 2008). The primary source of NE in the
brain, the locus coeruleus (LC), sends projections to both the ventral tegmental area (VTA), which
terminates in the vicinity of DA cell bodies (Jones and Moore 1977; Mejias–Aponte et al. 2009;
Simon et al. 1979; Weinshenker and Schroeder 2007). These noradrenergic afferents make synaptic
contact with VTA–DA neurons, which harbor several ... Show more content on Helpwriting.net ...
1993) whereas α2–receptor agonist, clonidine, regularized the firing pattern of the midbrain DA
neuron (Grenhoff and Svensson 1989). Additionally, idazoxan have been reported to either increase
or show no change in extracellular concentration of DA in the brain (Matsumoto et al. 1998; Devoto
et al. 2001). Thus, the effect of α2–receptor on DA neuronal activity and DA transmission is clearly
complex. Conversely, the role of desipramine (NET inhibitor) on DA transmission is also complex
since past studies have shown a conflicting role (Westerink et al. 1998; Linner et al.
... Get more on HelpWriting.net ...
10. A Brief Description of Schizophrenia
According to schizophrenia.com schizophrenia is a complex, debilitating mental disorder that 1–2%
of the world population experience. It is a disorder of the brain that affects how people think, feel,
and perceive. The purpose of this paper is to explore schizophrenia, in particular its signs,
symptoms, etiology and pathophysiology, and then examine drug treatment and their mechanism of
action. This will be followed by the prognosis for people with schizophrenia.
Signs and Symptoms
Early signs of schizophrenia include personality changes that involve abnormal emotional
responses, mood disturbance, or depression, as well as cognitive changes (Schizophrenia Society of
Canada, 2012). Symptoms of schizophrenia can be classified as positive ... Show more content on
Helpwriting.net ...
Dopamine Hypothesis
The current dopamine hypothesis suggests that schizophrenia is a result of dysregulation of
dopaminergic activity – there is an increase in dopamine D2 binding sites and there are prefrontal
D1 deficits (Moncrieff, 2009;). This means that there is over activity of dopamine in certain areas of
the brain – possibly leading to positive symptoms – and there is also under activity of dopamine in
other areas of the brain – possibly leading to negative symptoms. The original dopamine hypothesis
claimed that, rather than dysregulation, there was simply too much dopaminergic activity
(Moncrieff, 2009). The dopamine hypothesis came from identification of antipsychotics as
dopamine D2 receptor blockers (Nord, Farde, 2011; Miyake, Thompson, Skinbjerg, Dargham,
2011). Schizophrenia has been associated with the dysregulation of additional neurotransmitter
systems such as serotonin and glutamate (Moncrieff, 2009).
Drug Treatments
Antipsychotics have long been the primary drug treatment for schizophrenia (Lehne, 2010).
Antipsychotics are split into two main groups: 1) first generation antipsychotics (older,
conventional); and 2) second generation antipsychotics (newer, atypical).
First generation antipsychotics (FGAs), such as haloperidol are dopamine D2 antagonists. The most
common side effects include increased prolactin levels and extrapyramidal effects. Second
generation antipsychotics (SGAs), such as clozapine, are
... Get more on HelpWriting.net ...
11. Dopamine Hypothesis
The Dopamine Hypothesis of Schizophrenia Schizophrenia is a chronic, psychotic disorder in which
the affected individual feels a disconnection from reality, chaotic thought patterns, delusions,
hallucinations and various disturbances in behavioural, emotional and intellectual perception.
Schizophrenia is often linked to an irregular balance of dopamine in the brain and defects of the
frontal lobe (The American Heritage medical dictionary, 2007). The symptoms of schizophrenia can
be broken down into two categories: negative symptoms and positive symptoms. The negative
symptoms include an absence of normal function, including: alogia, anhedonia, depressed
appearance and apathy (Ayd, 1995), however this essay will focus primarily on the positive ... Show
more content on Helpwriting.net ...
To treat these psychoses, anti–psychotic medication is prescribed. Anti–psychotic medication works
by binding to a specific receptor in the brain, known as dopamine receptor D2 (Kapur, 2000). By
blocking this receptor, symptoms of psychosis are controlled. As symptoms of stimulant psychosis
are very similar to the positive symptoms of schizophrenia, anti–psychotic medication is the
preferred medication to treat affected individuals. Two types of anti–psychotic medications have
been developed, typical and atypical. Typical anti–psychotics have a high–potency and high affinity
to D2 receptors, however this can cause extrapyramidal effects and Parkinsonism (Golan &
Tashjian, 2012). Atypical anti–psychotics have a lower–potency and low affinity to D2 receptors and
less side–effects. Therefore, anti–psychotic medication must block an appropriate amount of D2
receptors as a deficiency of dopamine can cause extrapyramidal effects and even worsen the
negative symptoms whereas an excess results in psychosis. A cross–sectional neuroimaging study
reveals that the link between D2 receptors and extrapyramidal side effects occurs only after 78% of
D2 receptor occupancy (Kapur,
... Get more on HelpWriting.net ...
12. The Pros And Cons Of Schizophrenia
Schizophrenia is a complex, chronic, severe and disabling brain disorder that affects approximately
1% of all adults worldwide. It affects males and females equally (University of Maryland Medical
Centre). Signs and symptoms of Schizophrenia usually become apparent earlier in men that is
between the ages of 15 to 25 among men, and later in women, that is about 25 to 35 in women. The
symptoms of Schizophrenia are classified into: positive, negative and cognitive symptoms. The
positive symptoms include hallucinations, delusions, thought disorders, and movement disorders
(U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES, National institute of Mental
health). Negative symptoms include lack of pleasure in everyday life, lack of ability to begin and ...
Show more content on Helpwriting.net ...
For ethical reasons all our results and conclusions will be based on statistics without revealing who
among those we tested is affected or not affected to the public. From the adoption study we expect
Schizophrenia to be more in biological relatives of schizophrenic adoptees than in those of control
adoptees. It will also be of great interest to us to observe if the risk of the adopted away children to
develop Schizophrenia increases if both genetic parents are schizophrenics compared to if only one
of the genetic parents is schizophrenic. Some of the genes may appear to be associated with the
disorder in some ethnic groups and not in others, which would make it difficult to for us to say that a
specific gene is associated with Schizophrenia in general population. This may be because
predisposition for Schizophrenia is created by different combination and/or of genes in different
populations interacting with certain environmental factors. As association studies always follow
linkage studies which identify possible genomic regions or even specific candidate genes which
contribute to the development of a genetically influenced disorder. Results from linkage studies
depend on a variety of factors, including the presumption of the mode of inheritance, the
involvement of genes whose effects are large enough to detect and the extent to which family
members are diagnosed accurately as either affected or unaffected with a disorder in the
schizophrenia spectrum. Since all of these factors are problematic, it is will not be suprising that
results from linkage studies are less conclusive and have yet to identify genes that major effects to
the development of
... Get more on HelpWriting.net ...
13. Schizophreni A Long Term Mental Illness
Schizophrenia
Schizophrenia is a long term mental illness that will affect the way your mind works, changing your
behavioural patterns. It affects usually people who are in there late teens to young adults. This is due
to the natural changes in teen behaviour that happens to a teen when growing up such as sleep wake
cycle, emotions and motivation. These are a normal phase that happens normally to a teen but if the
get one more change which is symptoms of psychosis (hallucinations and delusions) then you will
have pass the diagnosis for schizophrenia. With a natural phase in teenage/young adult life sharing
so many similarities with the diagnosis of schizophrenia it is only certain that they are would be
more susceptible. "There are many types of schizophrenia the three main types of schizophrenia are;
the catatonic type, disorganised (hebephrenic) type and Paranoid type (Rethink,2014)." Catatonic
schizophrenia is the rarest type; this usually is involved sharp movements (over activity to stillness),
disorganised schizophrenia is more communication based, distorted behaviour makes it hard to
communicate with other. Behaviour could also be seen as unwell or poor mannerism. Paranoid
schizophrenia is the most common of all the schizophrenia type, these symptoms are usually just
hallucinations with little to no effect on anything else.
There is no clear cut understanding what is the actual cause of schizophrenia however we know that
it is a mixture of both genetics and
... Get more on HelpWriting.net ...
14. Primary Theories Of Schizophrenia Essay
There are three primary theories for schizophrenia that need to be considered:
The first theory being, the Genetic Theory. This theory proposes that schizophrenia is inherited and
passed through genes. An initial study shows, one in eight children of a schizophrenic parental
background develop this disorder, similarly another study concludes 75% of children will be
mentally healthy. Research also states, the illness occurs in 10% of persons with a first degree
relation to a family member with schizophrenia. Statistics are even high for an identical twin of a
person with schizophrenia, with a probability of 40–65% of developing the disorder.
Next is the Environmental/ Interpersonal Theory. This theory proposes that schizophrenia and
emotional disorders are directly correlated to a person's young upbringing in the home and parental
figures. It also proposes the idea that stress is a pivotal cause. A strong ... Show more content on
Helpwriting.net ...
The initial indication of schizophrenia being a factor of dopamine was amphetamine consumers.
Amphetamine causes several symptoms of schizophrenia including: delusions and hallucinations. In
schizophrenics there is an unsteady, high amount of dopamine in the brain. Antipsychotic drugs
work to lower the presence of dopamine on the brain by impeding dopamine receptors. There are
two primary dopamine receptors, D1 and D2. In schizophrenic patients the latter is split into D2, D3
and D4 subtypes. Dopamine activators are found in the striatum, prefrontal cortex and limbic system
of the brain. Clinical research has observed an increase of dopamine in the emotion controlling
striatum through PET and SPECT brain scans. Unfortunately there is no one pinpointed cause of
high dopamine levels. Many of these causes are: Agitation, anxiety, cognitive acuity, feeling of
pleasure, hedonism, high energy, high libido, insomnia, paranoia and
... Get more on HelpWriting.net ...
15. Neurotransmitters Function
A neurotransmitter is a chemical substance that is released in the nervous system at the end of the
nerve fibers. Its release results in the transfer of impulses and information across fibers or other
structure of the body. Dopamine is one of the neurotransmitters that are present in the nervous
system. It is the neurotransmitter that is responsible for controlling the centers of reward and
pleasure in brains of animals and humans. It is also responsible for making us acknowledge the
presence of areas that could lead to a pleasurable award and how to emotionally respond to this
stimulus. The brain is the site for the production of dopamine. The brain uses the dopaminergic
neurons that are present in the midbrain to manufacture dopamine. It ... Show more content on
Helpwriting.net ...
These include cocaine, fluoxetine, norepinephrine and GBR 12909. An experiment was carried out
that aimed to determine the effects of these substances on the performance of dopamine. First, a
control group was tested without the substances and it showed a high uptake of dopamine in the
olfactory tubercle, striatum and medial prefrontal cortex. . Then cocaine and GBR 12909 were
added, the uptake of dopamine in the presence of cocaine was completely inhibited in all parts that
had high affinity for it in the control group. The same occurred for GBR 12909 which was more
than fifty times more potent than cocaine even though half of the amount was applied. These
inhibitors block the dopamine transporter which is necessary for taking up dopamine. The dopamine
system that is most susceptible is the mesolimbic system. This is the pathway through which
dopamine is transferred from one part of the brain to another (S. Izenwesser et al,
... Get more on HelpWriting.net ...
16. Dopamine In Hypsychology
Dopamine is one of the main hypothesized physiological causes of schizophrenia (Brisch et. al.,
2014). It is involved in movement, pleasure, and cognition: all of which are impacted in
schizophrenia. Dopamine is a neurotransmitter or a chemical messenger. It is in the neurotransmitter
class of catecholamine and has both inhibitory and excitatory effects (Carlson, 2013). These effects
are seen on the postsynaptic neuron, depending on the neuron dopamine can either be inhibitory or
excitatory. Within the brain, there are three main systems that use dopamine as their
neurotransmitter. These three systems are the nigrostriatal system, mesolimbic system, and the
mesocortical system (Carlson, 2013).
The nigrostriatal system runs through the basal ganglia which is the part of the brain that controls
movement (Carlson, 2013). The mesolimbic system runs through the nucleus accumbens which
plays a role in rewarding stimuli (Carlson, 2013). The nucleus accumbens reinforces behavior such
as drug addictions. The mesocortical system has neurons in the ventral tegmental area and the
prefrontal cortex (Carlson, 2013). The parts of the brain impacted by the ... Show more content on
Helpwriting.net ...
Receptor sites are where molecules such as neurotransmitters react to other molecules. These D2
receptor sites are specialized for dopamine based on its molecular shape and composition. For
dopamine to have an impact on a cell such as a neuron in the brain, it has to bind to these receptor
sites. There is a higher level of dopamine seen in schizophrenia (Seeman & Kapur, 2000). It is not
just the excess of dopamine that can lead to schizophrenia, it is the excess of dopamine receptors.
The increased number of receptors makes the body more sensitive to the presence of dopamine. The
more receptors allows for the dopamine to go to more place "leading to a high release of dopamine"
(Seeman & Kapur, 2000, para.
... Get more on HelpWriting.net ...
17. Attention Deficit / Hyperactivity Disorder Case Study
Attention–deficit/hyperactivity Disorder (ADHD) is a behavioral disorder with a complex etiology.
Demonstrating a high genetic basis of ADHD symptomatology, several studies have shown an
association between this conditions and dopamine–related genes including the dopamine transporter
gene DAT1 and the dopamine receptor 4 gene DRD4. Additionally, various environmental factors
have been implicated, ranging from pre– and perinatal conditions such as maternal stress and
smoking during pregnancy, to many psychosocial environments including family instability.
Although most of the research has overcome the nature versus nurture debate, shifting their focus
towards the extent of contribution of each of the genetic and environmental components, ... Show
more content on Helpwriting.net ...
Different studies have investigated the etiology of ADHD, collectively reflecting the complexity and
multitude of dimensions and factors implicated in this disorder. In fact, Faraone and colleagues
(2005) have conducted studies showing that ADHD is related to significant genetic contributions,
with an estimated heritability of 76%. Most of the genes implicated are mainly associated with the
dopaminergic, serotonergic and glutamatergic pathways among others. Specific genes have been
determined to be major candidates of ADHD, with the dopamine receptor DRD4 on top of the list.
In addition to exploring biological influences on the etiology of any condition, it is equally
important to investigate the effects of environmental factors and how they might be involved in the
onset, development and progression of the pathology. When it comes to studying ADHD, different
environmental factors have been considered by researchers including birth and pregnancy
conditions, maternal smoking and alcohol consumption, along with psychosocial adversity among
many others (Langley, Holmans, van den Bree, & Thapar, 2007). That being said, it is important
today to consider both factors in the study of any psychosocial
... Get more on HelpWriting.net ...
18. Essay about The Dopamine Hypothesis of Schizophrenia
The Dopamine Hypothesis of Schizophrenia
Schizophrenia is a disease that has plagued societies around the world for centuries, although it was
not given its formal name until 1911. It is characterized by the presence of positive and negative
symptoms. Positive symptoms are so named because of the presence of altered behaviors, such as
delusions, hallucinations (usually auditory), extreme emotions, excited motor activity, and
incoherent thoughts and speech. (1,2) In contrast, negative symptoms are described as a lack of
behaviors, such as emotion, speech, social interaction, and action. (1,2) These symptoms are by no
means concrete. Not all schizophrenic patients will exhibit all or even a majority of these symptoms,
and there is some ... Show more content on Helpwriting.net ...
(2) However, there are some problems with this evidense. Amphetamines only mimic the positive
symptoms of schizophrenia. They do not produce any of the negative symptoms. Likewise, anti–
psychotic drugs are only affective on the positive symptoms of the disease. There is still some
evidense that schizophrenics do posess higher levels of dopamine, however, these increases are only
found in the striatum of the brain (7). The striatum is a region of the brain that receives its inputs
from and outputs to the cortex. Injury to the striatum results in problems with intiation and control
of motor behavior. (9) Also, there is evidence that the prefrontal cortex produces lower levels of
dopamine. (4) The prefrontal cortex is involved in the organization and coordination of information
to and from the cortex. (7)
The major support and refutation of the dopamine hypothesis has come from the examination of
dopamine receptors in these regions of the brain. There are two main types of dopamine receptors,
D1 and D2. However, within the category of D2 receptors, there are three subtypes, D2, D3, and D4.
(5) Through PET scan analysis of dopamine usage in the brain and post–mordum molecular analysis
of brain tissue, researcher were able to determine relative levels of dopamine receptors in patients
with schizophrenia compared to non–schizophrenics. Overall analysis of dopamine
... Get more on HelpWriting.net ...
19. Schizophrenia Is A Severe Mental Disorder Affecting More...
In this assignment, schizophrenia is going to be discussed and antipsychotics are going to be
critically analysed, from the World Health Organization they have stated that "Schizophrenia is a
severe mental disorder affecting more than 21 million people worldwide" (WHO, 2016).
Schizophrenia is characterized by changes in thinking, perception, emotions, language, sense of self
and behaviour. The main things that people have occur with this mental health issue are
Hallucinations where a person is hearing, seeing or feeling things that are not there in the first place.
They also get Delusions that are fixed false beliefs or suspicions that are firmly believed even when
there is evidence to suggest that they are not taking place, a person can also have abnormal
Behaviour they can be seen to have a strange appearance, they can start to self–neglect, have
incoherent speech, wandering aimlessly without a cause and sometimes be mumbling or laughing to
self.
The studies and issues
There are many problems with follow up studies of patients schizophrenia due to patients who are
labelled as having the condition varies from country to country, time to time and which psychiatrist
is dealing with the case. The patients chosen could be either sex, be of different age ranges, they
could be experiencing their first psychotic breakdown or could be more chronically ill. Any of the
factors could affect the course of the psychosis. A patient could be followed at certain times of their
life this
... Get more on HelpWriting.net ...
20. Methamphetamine (Or Ice): A Stimulant Analysis
Ice use in Australia, which is considerably higher than that of any other country, is at dangerously
high levels and is ever increasing. It is a national and worldwide problem that is causing its users
physical and psychological harm, as well as societal disconnection and misbehaviour
(Commonwealth of Australia, 2015). Methamphetamine, or "Ice", is a psychostimulant which
produces rewarding or pleasurable effects and behavioural alterations. It is known as a
psychostimulant because of it's classification as an amphetamine; which are classed as
psychostimulant drugs that abnormally speed up the functions of the users brain and body
(McCormack & Buckley, 2006).
The core activity of methamphetamine is to undertake endocytosis or monoamine reuptake within
the brain. Simply put, the reversal of ... Show more content on Helpwriting.net ...
This reversal process is responsible for the return of a neurotransmitter to the synaptic cleft, which
would otherwise be metabolised. This increases the chemical messages found at receptors. The
psychostimulant action of methamphetamine occurs through its ability to reverse the dopamine
transporter. This action can increase locomotor activity in its users (Swanson, Heath, Stratford, &
Kelley, 1997). Based on this, it would be expected that a dopamine receptor antagonist would reduce
the motor effect of methamphetamine administration. The aim of this report is to identify if the
administration of methamphetamine and it's stimulant effect play a role in locomotor activity, the
possible increase of motor behaviour, and whether or not this effect occurs
... Get more on HelpWriting.net ...
21. Understanding Schizophrenia and Psychosis
Schizophrenia and Psychotherapy Schizophrenia is a psychiatric disorder differentiated by
degeneration of thought processes and of emotional reaction. It is characterized by auditory
hallucinations, delusions, or disorganized speech and thought process along with considerable social
or occupational dysfunction. Onset of symptoms is usually during early adulthood. Diagnosis is
based on DSM–IV criteria for diagnosis of Schizophrenia (PubMed, 2010). It mainly affects the
cognition but behavior and emotion can also be involved. Schizophrenics can have certain
coexisting conditions such as major depression and anxiety disorders. These cognitive, emotional
and behavioral problems can lead to secondary problems like unemployment, academic difficulties
and social issues. Schizophrenics have higher tendency to suicide than general population which
makes their life expectancy 15 years less than the general population. The average life expectancy of
people with the disorder is 12 to 15 years less than those without, the result of increased physical
health problems and a higher suicide rate (about 5%). Following are the classification of
Schizophrenia according to DSM–IV Manual Paranoid type: delusions, hallucinations without
affecting the thought behavior, and cognition. (DSM code 295.3/ICD code F20.0) Disorganized
type: Though disorder and flat affect (DSM code 295.1/ICD code F20.1) Catatonic type: Agitated,
purposeless movements, occasional immobility, catatonic stupor
... Get more on HelpWriting.net ...
22. Four Theories Of Schizophrenia
There are many theories for schizophrenia that need to be considered. However, all these ideas are
strongly questioned.
The first theory being, the Genetic Theory. This theory proposes that schizophrenia is inherited and
passed through genes. As stated in the Epidemiology in Neurobiological Research by Tsung, Stone
and Faraone, "greater risks are associated with higher levels of shared genes. For example, third–
degree relatives share about 12.5% of their genes, and show a risk of 2% for developing
schizophrenia. Second–degree relatives share about 25% of their genes and show a risk of 6%. Most
first–degree relatives siblings, dizygotic (DZ) twins share about 50% of their genes and show a risk
of about 9%. Monozygotic (MZ) twins share 100%
... Get more on HelpWriting.net ...
23. Antipsychotics and Yoga Therapy as an Adjunct Treatment...
Antipsychotic Medications and Yoga Therapy as an Adjunct Treatment for Schizophrenia
Sarah Garrabrant
University of South Florida
Introduction
Schizophrenia is a severe form of mental illness classified in the DSM IV–TR as a Psychotic
disorder. It is characterize by broad impairments in cognition that place limitations on recovery
(Eack, 2012, p. 235). Antipsychotic drugs are the first line of treatment for Schizophrenic patients,
but come with adverse side–effects and many patients are treatment–resistant (Tandon, Nasrallahb,
& Keshavanc, 2010). Adjunct treatments that focus on cognition and coping with stress, along
with the antipsychotics have shown to be more effective (Sungur, Soyguur, Guuner, Uustuun, Cetin,
& ... Show more content on Helpwriting.net ...
Typical antipsychotic drugs occupy around 70–90% of D2 receptors at a common dosage
(Kleinman, Casanova, & Jaskiw, 1988).
Due to side effects and the nature of the illness, some patients do not keep continuous use of anti
psychotic treatment. It has been found that patients with light use of antipsychotics were more likely
to be hospitalized than continuous users. The average duration of anti–psychotic use was six months
in any single year and compared to individuals with a continuous pattern of anti psychotic treatment,
individuals with moderate or light use had odds for hospitalization, 52 or 72% greater (DosReis,
Johnson, Steinwachs, Rohde, Skinner, Fahey, & Lehman, 2008). First generation and Second–
generation antipsychotics
Researchers wanted to know who was more effective, first generation antipsychotics or second–
generation antipsychotics (Kane, 1999). The CATIE trial compares first and second generation
antipsychotics, comparing first generation perphenazine with second generation drugs, olanzapine,
quetiapine, risperidone, and ziprazidone. Overall, olanzapine did better than other treatments,. What
surprised researchers most is that first generation antipsychotic, perphenazine, was similar in
effectiveness to three of the four second–generation antipsychotics (Liberman & Stroup, 2010).
It has been found that 30% of patients fail to
... Get more on HelpWriting.net ...
24. Pharmacology Report On Halooperidol
Pharmacology Report – Haloperidol
http://psychrights.org/states/alaska/Matsutani/Exhibits2Motion4PrelimInj/78–24–100324ExE13.pdf
http://onlinelibrary.wiley.com/doi/10.1038/sj.bjp.0700989/full
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3298219/ deffo this
http://bmcpsychiatry.biomedcentral.com/articles/10.1186/1471–244X–13–240 shove it in
somewhere (tox)
Discovery, structure, class and associated physiochemical properties
Haloperidol is an butyrophenone class antipsychotic drug discovered in the 1950s by a Belgian
company 'Janssen Pharmaceutica.' It was found through research conducted on 'painkilling'
analgesic molecule derivatives from methadone and pethidine. This lead to the creation of
phenoperidine, after further study of its analogues ... Show more content on Helpwriting.net ...
and Alamo, C. (2009). The consolidation of neuroleptic therapy: Janssen, the discovery of
haloperidol and its introduction into clinical practice. Brain Research Bulletin, [online] 79(2),
pp.130–141. Available at: http://www.sciencedirect.com/science/article/pii/S036192300900032X
[Accessed 9 Nov. 2016].
Maddison, J., Page, S. and Church, D. (2008). Small animal clinical pharmacology. 1st ed. Elsevier
Health Sciences, p.131.
Puri, B. (2012). Textbook of Clinical Neuropsychiatry and Behavioral Neuroscience 3E. 3rd ed.
Taylor & Francis, p.63.
SASIKIRAN GOUD, E. and KRISHNA REDDY, V. (2013). DEVELOPMENT AND
VALIDATION OF A REVERSE–PHASE LIQUID CHROMATOGRAPHIC METHOD FOR
ASSAY AND RELATED SUBSTANCES OF HALOPERIDOL FOR 50MG/ML AND 100MG/ML.
International Journal of Pharmacy and Pharmaceutical Sciences, [online] 5. Available at:
http://www.ijppsjournal.com/Vol5Suppl2/6839.pdf [Accessed 9 Nov. 2016].
Seeman, P. (2002). Atypical antipsychotics: mechanism of action. Canadian Journal of Psychiatry,
[online] pp.27–38. Available at: https://www.ncbi.nlm.nih.gov/pubmed/11873706 [Accessed 11 Nov.
2016].
Seeman, P. (2010). Dopamine D2 Receptors as Treatment Targets in Schizophrenia. Clinical
Schizophrenia & Related Psychoses, [online] 4(1), pp.56–73. Available at:
https://www.ncbi.nlm.nih.gov/pubmed/20643630 [Accessed 9 Nov.
... Get more on HelpWriting.net ...
25. Psychological Definition Of Wrath
Definition of Wrath: Although anger is biologically innate, wrath is an extreme form of this
emotional response. It is the chronic tendency for aggressive behaviour characterized by the
inability to control an emotional reaction to a stimulus which is perceived as a threat or source of
frustration. Wrath is irrational, excessive, and impulsive behaviour often accompanied by the
incapacity to foresee consequences and hazards associated with one's actions.
Molecular Entities
Epinephrine and Norepinephrine: neurotransmitters/hormones associated with anger–related
behaviour that support the body during aggression by increasing anxiety/tension.
GABA: Excitatory responses such as aggression can be modulated through Gamma–Aminobutyric
acid (GABA), ... Show more content on Helpwriting.net ...
The blockade of D2 receptors has been used as a treatment for aggression (Haloperidol), however
D2 receptors also regulate other emotions, motivation, executive function, motor planning and
reproductivity.
Serotonin: is an inhibitory neurotransmitter found throughout the brain. Several studies have
demonstrated that low levels of serotonin have been correlated with aggressive behaviour,
specifically in the limbic system, orbitofrontal cortex (OFC) and amygdala. There exist seven
families of serotonin 5–HT receptors, (5–HT1 – 5–HT7) and a few families have several
subpopulations, however a preliminary literature review indicates that are three main Serotonin
receptors implicated in aggression and anger in the OFC: 5–HT1A, 5–HT2A, 5–HT1B .
Strategy: Literature has indicated that the agonism of 5–HT1A, 5–HT1B and 5–HT2A receptors is
responsible for the reduction of aggressive behaviours. However, the hyperactivity of these various
receptors is associated with varying side effects. For instance: Although agonism of the 5–HT1A
receptor has been shown to decrease aggression, it has also been shown to interfere with body
temperature, blood pressure, and heart rate regulation . Similarly, targeting the 5–HT2A receptor has
been shown to cause uncontrolled motor behaviour and hallucinations. Thus, our primary strategy
for reducing aggression involves the agonism of one of various of the 5HT receptors, however,
... Get more on HelpWriting.net ...
26. Symptoms And Treatment Of Huntington 's Disease
Huntington 's Disease Huntington 's disease is an inherited neurodegenerative disease that is caused
by a mutation on the HTT gene. It typically effects persons in their third to fifth decade of life and
can be passed onto their children. Neurons in the brain waste away or degenerate in different areas
causing the characterizing symptoms, such as dance–like movements and mental decline. Diagnosis
and prognosis can be devastating to both individual and family. However, there are genetic tests that
can help to predict the probability of developing symptoms of the disease. There is no cure for this
debilitating disease; only symptom control and maximization of comfort can be prescribed until
future research finds a cure. This paper will review origins and symptoms, in addition to treatments
and future treatments.
Origins
Genetics The gene HTT is located on the short arm of chromosome 4 and is present in everyone;
however, it is the mutation of that gene that causes Huntington's disease. The mutation presents as
an error in the CAG repeat equal to additional repeats more than is normal. Normal genotypes have
less than 36 CAG repeats, anything above 36 results in an unstable gene (Scott, 2011). If a person
has 36 to 39 repeats, he or she is genetically considered to have Huntington 's, but may not develop
the symptoms of Huntington 's; however, his or her offspring will definitely have a great probability
of developing symptoms (Scott, 2011). A person with 40 or more repeats
... Get more on HelpWriting.net ...
27. Alcohol Reward System
Alcohol Dependence as a Product of the Reward System
To demonstrate an understanding of alcohol dependence, the reward system, a proponent of
addiction, is briefly discussed in the news article. Although the article outlines the basic mechanisms
underlying the reward pathway, it fails to encompass the complexities associated with neural
reward, consequently highlighting the fallacies that exist within the article. Alcohol addiction
possesses the capacity to induce changes in the reward and motivational systems, introducing
deficiencies in inhibitory control (Koob and Volkow, 2010). Alcohol dependence may be
characterized as a reward deficit disorder, highlighted by both impulsive and compulsive substance
intake. Essentially, alcohol induces a state of ... Show more content on Helpwriting.net ...
Research has demonstrated that an increase in the concentration of dopamine in the VTA enhances
the desire of reward–related stimuli (Lee, 2013). The effect of alcohol intake is not directly
correlated to dopamine receptors; but involves the indirect increase of dopamine in the reward
pathway, or MDS (Boileau, Assaad, Pihl, Benkelfat et al., 2003). The increase in dopamine is
attributed to alcohol directly affecting the GABA system – inhibitory neurotransmitter in the brain,
and the endorphin system – peptide hormones that bind to opioid receptors and affect sensation of
pain. Neurons from both the GABA and endorphin systems extend into the MDS. When directly
stimulated by alcohol, both the GABA and endorphin pathways release dopamine into the reward
pathway, ultimately accounting for alcohol's capacity to indirectly induce an increase of dopamine
(Boileau et al., 2003; Ramchandani, 2005) (Appendix B). Subsequently the increase of dopamine in
the MDS enhances the attractiveness of reward–related
... Get more on HelpWriting.net ...
28. Is Schizophrenia A Class Of Mental Disorders?
Schizophrenia is a class of mental disorders often symptomatic of a broad spectrum of behaviours
which ultimately fail to determine what is real. Some of the symptoms that make up the spectrum of
schizophrenia include hallucinations, invalid or illogical beliefs or thought processes, and abnormal
social expression. It is worth noting that schizophrenia does not mean multiple personality disorder
but rather a separating of mental function and is also rarely diagnosed separately but along with
other conditions, such as depression, mania, and anxiety disorders. As to the causes of
schizophrenia, both genetic [1] and environmental factors [2] have been found to influence the
progress of schizophrenia, but there is still much which is unknown ... Show more content on
Helpwriting.net ...
counselling) and antipsychotics. Antipsychotics do not cure the subject of their psychosis but merely
treat the positive symptoms by mainly blocking the dopamine receptors in the brain. Hence, new
drugs and treatments are continuously in the pipeline to find a drug that manages the symptoms of
schizophrenia with relatively few (preferably none) side–effects.
Antipsychotic drugs are classified as either typical or atypical, based on their relative potency and
side–effects. This classification is usually substituted with referring to typical as first generation and
atypical as second generation, due to atypicals comparatively safer side–effects. However, it has
been argued that due to the severe side–effects of both, the amount individual variation between
psychotic patients, the patient's tolerance to individual drugs, and the fact that antipsychotics treat
symptoms rather than the psychosis, it might be better to class the drugs in regards to their
mechanisms rather than their relative potencies [6][7]. Typical antipsychotics antagonise the D2
receptors and atypical antipsychotics target the D2 receptors among others (e.g. D3 and 5HT2
receptors).
Currently, the main drugs used to treat schizophrenia include clozapine, risperidone and haloperidol.
It is still debatable which class, as stated above, whether typical or atypical antipsychotics are better
and produce relatively safer side–effects among
... Get more on HelpWriting.net ...
29. Attention Deficit Hyperactivity Disorder ( Adhd )
Attention–Deficit Hyperactivity Disorder (ADHD), according to the textbook, is a lifelong
neurological development disturbance that causes inattention and hyperactivity problems (Wicks–
Nelson & Israel, 2015, p. 217). Many of those who have ADHD also suffer from one or more type
of learning disability, because their attention issues that inhibit their ability to focus on the materials
being taught at the moment (McNamara, J. [October 19, 2016], Lecture #6, Brock University).
According to the Diagnostic and Statistical Manual of Mental Disorders, the fifth edition (DSM–5),
there are three categories for ADHD, the inattentive type, hyperactivity type, and the combined type
(Wicks–Nelson & Israel, 2015, p. 223–225). In this scenario, there are various aspects of Kate's
diagnosis that could affect the understanding of ADHD for those around her. From a biological
perspective, the composition of a child's chromosomes is arbitrarily taken from both parents which
they each contribute a random fifty percent (McNamara, J. [September 28, 2016], Lecture #4, Brock
University; Wicks–Nelson & Israel, 2015, p. 41–42). Each gene carries precise information and
particular function through transmission (McNamara, J. [September 28, 2016], Lecture #4, Brock
University). Family members who are intimately related are also more vulnerable to any physical or
psychological disorders due to the greater probability of passing on the gene (Wicks–Nelson &
Israel, 2015, p. 43–44). Studies have shown
... Get more on HelpWriting.net ...
30. Dopamine Receptors
INTRODUCTION
In neural signaling, axons transmit trains of action potentials from soma to dendrites, where synaptic
transmission takes place. Until a decade ago it was thought that axonal trunk doesn't play any
important role in neural communication except conducting spikes faithfully. However, it has become
clear that because of the existence of many voltage– and ligand–gated ion channels in the non–
synaptic areas of axons, different neuromodulators, especially monoamines, may have some effects
on the excitability of axonal membrane via activating or deactivating these channels, and therefore,
change the shape or conduction velocity of spikes. Consequently, spikes arriving at the pre–synaptic
terminals may not be exactly the same as those ... Show more content on Helpwriting.net ...
For example, there is an axonal serotonin–sensitive region in the lateral gastric neurons of the crab,
which spikes could be initiated there, propagate to axonal terminals, and change the output of the
neuron. (Meyrand, Weimann, & Marder, 1992) Also, it seems that serotonin via 5–HT1A receptors
could modulate Na+ current, and then inhibit the spike initiation at the axon initial segment. (Cotel,
Exley, Cragg, & Perrier, 2013) In addition, like dopamine, the axonal membrane excitability could
be increased by serotonin in the unmyelinated nerve fibers. (Lang, Moalem–Taylor, Tracey,
Bostock, & Grafe,
... Get more on HelpWriting.net ...
31. Essay On Dopamine
Taking a look inside of the basal ganglia specifically within the substantia nigra and ventral
tegmental space, the production of dopamine occurs. Dopamine is a neurotransmitter that effects
provide both excitatory and inhibitory responses with axon networks. Within the substantia nigra
amino acids known as tyrosine reacts with tyrosine hydroxylase in order to produce L–Dopa which
is then reacted with L–Dopa decarboxylase in order to finally produce dopamine. Once produced
dopamine has been found responsible for initiating movement, helpful in attention and learning.
Therefore, the synthesis of dopamine occurs within the substantia nigra, but this is only where the
cell bodies are located. The neurons project onto the ventral tegmental area ... Show more content on
Helpwriting.net ...
Unfortunately, when this hyperactivity occurs and Dopamine continuously binds to D2 receptors
thendopamine acts to cause schizophrenic type behaviors. It has been thought that such a
hyperactivity, which can cause hallucination are the primary reason for schizophrenia but in recent
studies there may be other factors that cause schizophrenia. These factors are still unclear. However,
for now tyrosine an amino acid is converted into L–Dopa which then is converted into dopamine.
Dopamine is then released into a synapse which can influence an individuals thought processes
specifically it can cause one to experience severe hallucinations a and delusions of people and
objects that do not exist ultimately linking dopamine and schizophrenia. However it should be
known that the "Dopamine Hypothesis of Schizophrenia" is currently being disputed but for now the
scientific community believes that schizophrenia may be caused by hyperactivity of dopamine likely
due to the inability to inactivate and reuptake dopamine in the synapse and repeated binding to D2
... Get more on HelpWriting.net ...
32. Diagnosis And Treatment Of Adhd
Another developing concern in regard to the prevalence of ADHD is that there is a growing shifts in
the onset span and in the population currently diagnosed with ADHD. A clinical practice guideline
published by the American Academy of Pediatrics (2011) reported the expansion of the age range in
regard to diagnosis and treatment of ADHD from 6 through 12 years of age to 4 through 18 years of
age. More recent studies substantiated that a majority of ADHD cases persists well into adulthood in
spite of the widespread recognition of this neurodevelopmental disorder's onset for which it only
occurs in childhood and adolescent years (Simon, Czobor, Balint, Meszaros, & Bitter, 2009).
Furthermore, some adults are diagnosed with ADHD without having been diagnosed previously
(National Resource Center on ADHD, 2013). Moreover, Asherson et al. (2012) raised a crucial
argument in their research that adults with ADHD likely underestimate or ignore the influence
brought by the disorder and attempt to compensate for or rationalize the deficiencies by adapting
lifestyle that works for them. Thus, it is likely that the current prevalence of ADHD in adults is
underreported. Essentially, it indicates that ADHD is a life–long neurodevelopmental psychiatric
disorder attributed to a sophisticated combination of genetic and environment components. As
ADHD is categorized in neurodevelopmental disorders in the DSM–5, this psychiatric disorder
involves selective impairment in relation to neurological
... Get more on HelpWriting.net ...
33. A Research Done By Morelli, Rameson, And Lieberman About...
Various articles and literature works coupled with the ongoing happenings clearly indicate that
happiness has no price tag. Since the beginning of human evolution, there has been a saying that
"money cannot buy anyone happiness." Happiness refers to emotions, and it is dependent on
people's choices (Landau, 2008). Finding oneself in a place where material properties and social
status are crucial, many people's happiness in such cases would be dependent on these things. For
the purpose of understanding this issue, this paper critically analyses a research done by Morelli,
Rameson, and Lieberman about happiness.
Question 1: The Research methods
First, there is the observational method. The researchers used the observational method to
identifying how certain characters tend to be influenced by environmental changes. For instance, the
researchers review the study conducted by Morelli and Lieberman, where the volunteers were
instructed to look at pictures at their free time and memorize the eight digits assigned to them by the
researchers. Some individuals showed reduced empathy, while others were able to feel things deeply
(Kluger, 2013). This kind of research methodology is mainly concerned with psychological or
behavioral traits of the study population.
Generally, observations are cheap, and the researcher uses few resources in conducting the research.
Conversely, observations consume a lot of time since researchers have to wait for the observational
traits of the
... Get more on HelpWriting.net ...
34. Atypical Antipsychotics.A Brief Overview. Dr. Vipin
ATYPICAL ANTIPSYCHOTICS A BRIEF OVERVIEW Dr. VIPIN KUMAR, MBBS, DTCD, MD
(PSYCHIATRY); CONSULTANT PSYCHIATRIST, AURANGABAD, BIHAR
The atypical antipsychotics or second generation antipsychotics (SGA) are a group of antipsychotics
that were introduced in the clinical practice during the early 1990. All over world these agents are
most commonly prescribed for Schizophrenia and other illnesses with psychotic symptoms. This
article will focus on brief overview of the atypical antipsychotics as a class and brief description of
selected atypical antipsychotics.
The main feature that distinguishes SGAs from first generation antipsychotics (FGAs) is that they
tend to cause less ... Show more content on Helpwriting.net ...
There was no significant difference between patients treated with FGA and patients treated with
SGA in scores on the quality of life scale.
Molecules available in the Indian market: Olanzapine, Quetiapine, Clozapine, Aripiprazole,
Amisulpiride, Risperidone, Iloperdone, Ziprasidone, Paliperidone, Asenapine.
They share the common property of blocking D2 and 5HT2A receptors. However no two molecules
are the same. The degrees to which they block D2 and 5HT2A receptors as well as activity at myriad
of other receptors make them very much different from one another within the class. And this
difference is reflected more in side effects profile than efficacy. Majority of times it is in fact the
side effect profile of the drug that guides clinicians while choosing among many drugs.
Indications
Schizophrenia: Acute exacerbations and maintenance
Acute mania and maintenance of bipolar mood disorder
Bipolar depression
Treatment resistant depression
Delirium
Behavioral disturbance in dementia
Behavioral disturbance in children
Borderline personality disorder
Common side effects
Sedation, headache, hypotension, postural dizziness, dry mouth, constipation
Troublesome side effects
Extrapyramidal symptoms (akathisia etc), weight gain, impaired glucose tolerance, dyslipidemia,
hyperprolactinemia and galactorrhoea
36. Attention Deficit / Hyperactivity Disorder
Neurodevelopmental Disorders Specifically Attention–Deficit/Hyperactivity Disorder Abby Hull
Southern Illinois University Carbondale Neurodevelopmental Disorders Specifically Attention–
Deficit/Hyperactivity Disorder "ADHD: we think more things before breakfast than most people
think all day" ("We Think..., 2012). "Neurodevelopmental disorders are a group of disorders in
which the development of the central nervous system is disturbed. These disruptions can include
developmental brain dysfunction, which can manifest as impaired motor function, impaired
learning, impaired language or non–verbal communication" ("Neurodevelopmental disorders,"
2015). A specific type of neurodevelopmental disorder, ... Show more content on Helpwriting.net ...
These children often have trouble concentrating on the task at hand and if the symptoms are severe
and persistent enough and if it begins to interfere with functioning or development, the child would
meet the criteria for diagnosis of ADHD (Kring, Johnson, Davison, Neale, 2014). Children with
ADHD also may have difficulty building friendships and relationships with others due to their
aggressive and intrusive behavior although they seem friendly and talkative. Problems usually occur
in two or more areas of a person's life: home, work, school, and social relationships (Psych Central,
2015). The prevalence rates of attention–deficit hyperactive disorder vary between age groups. The
textbook states that the consensus on prevalence estimates is that about three to seven percent of
school–aged children worldwide currently have ADHD along with two to five percent of adults
(Kring et al., 2014). This is also consistent with the findings by the Center for Disease Control
where 4.4 million youth between the ages of four to seventeen have been diagnosed with ADHD;
using these prevalence rates, it can be estimated that in a classroom of twenty–five to thirty children,
at least one of those children will have ADHD (Austin, Staata Reiss, & Burgdorf, 2007). The age of
onset of attention–deficit hyperactive disorder has research supporting the theory that it is a
physiological condition and is present at birth. With this being said, most patients do not
... Get more on HelpWriting.net ...
37. Nature vs Nurture Essay
Nature vs Nurture
Most of us have an intuition that, although our genes provide advantages and constraints, we retain
great control over our lives. However, we are developing a second, competing intuition that, like it
or not, our genes determine our abilities, our preferences, and our emotions. We would like to think
we are much more than the sum of our genes, but scientists have apparently demonstrated that our
genes determine some of our most complex behavioral and cognitive characteristics.
The focus on genes as the primary mode of biological explanation has been especially clear in the
marketing of the Human Genome Project. In support of this project, Robert L. Sinsheimer, biologist
and former chancellor at the University of ... Show more content on Helpwriting.net ...
1987), and alcoholism (Gelernter et al. 1991). Authors of two studies claiming to have found a gene
for manic–depression (in two different places), have both published retractions of their conclusions
(Barron et al. 1993, Kelsoe et al. 1989), unusual and embarrassing events among scientists.
Research in linking genes to complex human mental and behavioral characteristics has been
tremendously successful in molding public opinion, in he absence of much lasting scientific
evidence.
The relationship between a gene and a human behaviour is rarely, if ever, a one–to–one
correspondence, even though disruption of a single gene occasionally has a dramatic effect on
behaviour. Nor can one quantify the contribution of genes as a whole to any particular behavior or
cognitive ability. Instead, each gene is a single player in an intricate story, involving non–additive
interactions of genes, proteins, hormones, food and life experiences, thus leading to effects one
variety of cognitive and behavioural functions. Our thoughts, emotions, and behaviors certainly
have biological mechanisms, but this does not mean we can separate and quantify the genetic
contributions to these processes.
References:
Baron, M., N. Risch, R. Hamburger, B. Mandel, S. Kushner, M.Newman, D. Drumer, and R.H.
Belmaker. 1987. Genetic Linkage Between X–Chromosome Markers and Bipolar
... Get more on HelpWriting.net ...
38. Dopamine Hypothesis Of Schizophreni The Psychotic Syndrome
Dopamine hypothesis of schizophrenia The psychotic syndrome at the core of schizophrenia appear
to be invariable across cultures (What is schizophrenia?, 1988). The term schizophrenia refers to
schizein to "split" and phren "mind" was introduced by Eugen bleuler in 1857–1939 (Breedlove &
V. Waston, 2013). This psychotic syndrome is neurodevelopmental disorder involving the
breakdown in the relation between thought and a major impairment of logical structure of
dissociative thinking (Bencherif, Stachowiak, Kucinski & Lippiello, 2012). Consequently, the
disorder is characterised by many behavioural, anatomical and neurochemical abnormalities
(Bencherif, Stachowiak, Kucinski & Lippiello, 2012). The behavioural states ... Show more content
on Helpwriting.net ...
( Häfner & An der Heiden,1997). The evidence of dopamine hypothesis of schizophrenia can be
supported by the experiments on the availability of D2 receptors and amphetamine studies.
Furthermore, studies related to antipsychotic drug treatment can demonstrate the improvement of
positive symptoms of schizophrenia. The current essay will support the dopamine hypothesis of
schizophrenia by using empirical research.
The classic dopamine hypothesis state that the excess of dopamine is subcortically related with the
positive symptoms (Abi–Dargham, 1999). In an experiment, firstly brain scans were done to achieve
baseline D2 receptor availability (Abi–Dargham, 1999). The fluctuations in the synaptic dopamine
levels were measured using in vivo binding techniques, the competition between endogenous levels
of the neurotransmitter and the radiotracer for binding to the D2 dopamine receptors (Abi–Dargham,
1999). Injection of amphetamine, cause dopamine to be released into the synapse (Abi–Dargham,
1999). Resulting high levels of concentration of the endogenous dopamine in contrast, decreasing
the amount of radiotracer available to bind to the dopamine receptor (Abi–Dargham, 1999). The
amount of dopamine released after amphetamine can be observed through the difference between
the two brain scans (Abi–Dargham, 1999). As a result transmission of dopamine was increased in
schizophrenic subjects compared
... Get more on HelpWriting.net ...
39. The Dopamine System Plays A Critical Role Of...
The mesolimbic dopamine system plays a critical role in psychostimulant–induced locomotor
activity (Hall, Powers & Gulley, 2009). Dopamine (DA) is a monoamine that has been long
associated with the brain's reward systems, and more recently, its effects on animal behaviour have
been investigated (Barron, Sovik & Cornish, 2010). While becoming the most broadly used illicit
drug world wide, Methamphetamine (MA) is an addictive psychostimulant which causes the brain to
release excessive amounts of the chemical neurotransmitter DA, controlling pleasure (Carati &
Schenk, 2011). It has been used to suppress food intake and most commonly, increase mental
alertness and physical endurance (Seiden, 2004). When linking MA to the brain, its primary action is
to elevate the levels of extracellular monoamine neurotransmitters, including dopamine, by
promoting their release from the nerve endings (Xie & Miller, 2009). Evidence has shown that these
drug–induced neuropathological changes might underlie deficits in cognitive behaviours in chronic
MA abusers. MA preferentially increases synaptic dopamine concentrations in the mesolimbic
dopaminergic system and initiates stimulating behavior (Di Chiara & Imperato, 1988). These ideas
are further strengthened by data from animal studies showing that MA neurotoxicity is associated
with impairments in motor learning (Daberkow, Kesner & Keefe, 2005) in rodents.
Considerable evidence suggests that the locomotor activating effects of MA are mediated
... Get more on HelpWriting.net ...
40. Glutamate Theory Of Schizophrenia Essay
Schizophrenia is a chronic neurological disease that results in a combination of positive, negative,
and cognitive symptoms. Positive symptoms of Schizophrenia include hallucinations and delusions.
Negative symptoms of Schizophrenia most commonly consist of avolition, anhedonia, and alogia.
Cognitive symptoms affect the person's cognition. Patients with the disorder have disorganized
speech and behavior, deficits in learning and memory, as well as deficiencies in abstract thinking
and problem solving. Positive symptoms of Schizophrenia are commonly attributed to the
abnormally high levels of dopamine (Konradsson–Geuken, slide 25). While there is no current cure
for Schizophrenia there are different treatments that prove to help certain aspects of the disorder. ...
Show more content on Helpwriting.net ...
Levels of glutamate in affected patients are lower than normal. Therefore drugs agonizing NMDA
receptors would be a beneficial treatment. The glutamate hypothesis of Schizophrenia states that
PCP and other NMDA receptor antagonists lead to the positive and negative symptoms as well as
cognitive impairment of Schizophrenia in normal and schizophrenic patients. However those
symptoms are heightened in schizophrenics. These individuals have altered expressions of NMDA
receptor subtypes in the prefrontal cortex, which leads to less glutamate output. D–aspartate is an
endogenous agonist of NMDARs. Increased levels of D–aspartate is shown to "improve brain
connectivity... and protect against abnormal circuit activation induced by psychotomimetic drugs"
(Errico et al, pg 7, 2015). Postmortem studies of Schizophrenic brains display decreased levels of
D–aspartate in the prefrontal cortex and striatum. Furthermore, the dopamine and glutamate systems
appear to be linked. NMDA hypo–function in the prefrontal may cause DA dysregulation, which
further hinders NMDA plasticity. The interconnected systems cause a patient to deteriorate in one
full
... Get more on HelpWriting.net ...