The document discusses several key neurotransmitters: dopamine, GABA, serotonin, and acetylcholine. For each one, it outlines their mechanism of action, where they are found in the body, symptoms of excess and insufficiency, nutritional building blocks, common medications, and how levels may change with age. The document provides a high-level overview of several major neurotransmitters in the brain and nervous system.

1. Neurobiology:
Dopamine, GABA,
Serotonin, Acetylcholine
Dr. Dawn-Elise Snipes PhD, LPC-MHSP, LMHC
Executive Director, AllCEUs.com

2. Objectives
 Define Neurobiology
 For the following neurotransmitters, Dopamine,
GABA, Serotonin, Acetylcholine, identify
 Their mechanism of action/purpose
 Where they are found
 Symptoms of excess & insufficiency
 Nutritional building blocks
 Medications
 Neurological changes over the lifespan

3. What is Neurobiology
 Neurobiology is the study of the brain and
nervous system which generate sensation,
perception, movement, learning, emotion,
and many of the functions that make us
human

4. Dopamine
 Mechanism of action/purpose
 Movement
 Memory
 Pleasurable reward
 Behavior and cognition
 Attention
 Sleep
 Mood
 Learning

5. Dopamine
 Mechanisms of Action
 Precursor, L-DOPA is synthesized in brain and
kidneys
 Dopamine functions in several parts of the
peripheral nervous system
In blood vessels, it inhibits norepinephrine release
and acts as a vasodilator (relaxation)
In the pancreas, it reduces insulin production
In the digestive system, it reduces gastrointestinal
motility and protects intestinal mucosa
In the immune system, it reduces lymphocyte
activity.

6. Dopamine
 Symptoms of excess
Unnecessary movements, repetitive tics
Psychosis
Hypersexuality
Nausea
Most antipsychotic drugs are dopamine antagonists
Dopamine antagonist drugs are also some of the
most effective anti-nausea agents

7. Dopamine
 Symptoms of insufficiency
 Insufficient dopamine
Negative symptoms of schizophrenia
Pain
Parkinson’s Disease
Restless legs syndrome
Attention deficit hyperactivity disorder (ADHD)
Neurological symptoms that increase in frequency with
age, such as decreased arm swing and increased
rigidity.
Changes in dopamine levels may also cause age-related
changes in cognitive flexibility.

8. Dopamine
 Symptoms of excess & insufficiency
 Insufficient dopamine
Lack of motivation
Fatigue
Apathy, Inability to feel pleasure
Procrastination
Low libido
Sleep problems
Mood swings
Hopelessness
Memory loss
Inability to concentrate

9. Dopamine: Age Related Changes
 Dopamine levels decline by around 10% per
decade from early adulthood and have been
associated with declines in cognitive and motor
performance
 Dopamine levels are also impacted by
availability of estrogen
https://www.ncbi
.nlm.nih.gov/pmc
/articles/PMC259
6698/

10. Dopamine
 Nutritional building blocks
 Eating a diet high in magnesium and tyrosine rich
foods will ensure you’ve got the basic building blocks
needed for dopamine production.
 Here’s a list of foods known to increase dopamine:
Chicken
Almonds
Apples
Avocado
Bananas
Beets
Chocolate
Green leafy
vegetables
Green tea
Lima beans
Oatmeal
Sesame &
pumpkin seeds
Turmeric
Watermelon
Wheat germ

11. Dopamine
 Medications
 Most common dopamine antagonists (positive
symptoms)
Risperdone, Haldol, Zyprexa
Metoclopramide (Reglan) is an antiemetic and
antipsychotic
 Most common dopamine AGONISTs (Parkinson’s,
Restless Legs) (negative symptoms)
Mirapex & Requip Excess: Unnecessary
movements, repetitive
tics, Psychosis,
Hypersexuality
Nausea
Insufficiency:
Depression

12. Glutamate
 Is an amino acid (present in most high protein
foods)
 Most prevalent excitatory neurotransmitter
 Used to make GABA (teeter-totter)
 Facilitates learning and memory
 Excess glutamate is associated with
 Panic attacks / anxiety
 Impulsivity
 OCD
 Depression
Chang L, Jiang CS,
Ernst T (January
2009). "Effects of age
and sex on brain
glutamate and other
metabolites". Magn
Reson Imaging. 27
(1): 142–5.

13. Glutamate
 Availability declines with age
 Affected by serotonin availability
 Insufficient
 Agitation
 Memory loss
 Sleeplessness
 Low energy level
 Depression

14. GABA
 Mechanism of action/purpose
 Anti-anxiety, Anti-convulsant
 GABA is made from glutamate
 GABA functions as an inhibitory neurotransmitter
 GABA does the opposite and tells the adjoining cells
not to “fire”
 Where is it found
 Close to 40% of the synapses in the human brain
work with GABA and therefore have GABA receptors.

15. GABA
 Symptoms of excess
 Excess sleepiness
 Shallow breathing
 *Increased blood pressure
 Symptoms of insufficiency
 Anxiety
 Depression
 Difficulty concentrating
 Insomnia
 Seizure disorders

16. GABA
 Nutritional building blocks
 Fermented foods sauerkraut, yogurt, kefir
 Almonds & walnuts
 Cherry tomatoes
 Bananas
 Brown rice
 Potatoes
 Oats
 Lentils, navy & lima beans
 Vitamin B6, if deficient, may impair the production
of GABA as it is a cofactor nutrient.

17. GABA
 Medications
 Drugs that increase the available amount of GABA
typically have relaxing, anti-anxiety, and anti-
convulsive effect
 Gabapentin (neurontin) is a GABA analogue used
to treat epilepsy and neurologic pain.
 Benzodiazepines and Barbiturates including GHB,
Valium, Xanax

18. Serotonin
 Mechanism of action/purpose
 Helps regulate
Mood
Cardiovascular functioning
Memory
Intestinal motility
Sleep patterns
Appetite
Pain

19. Serotonin
 Where is it found
 Brain
 Gut/Intestines
 Symptoms of excess (Serotonin Syndrome)
 Shivering
 Diarrhea
 Muscle rigity
 Fever
 Seizures
 Irregular heartbeat

20. Serotonin
 Symptoms of excess
 Depression
 Apathy, Emotional flatness or dullness
 Passivity
 Insomnia and other sleep problems
 Difficulty concentrating and learning
 Poor memory; amnesia
 Difficulty making decisions and acting on them
 Sexual dysfunction

21. Serotonin
 Insufficiency
 Depression
 Anxiety
 Pain sensitivity
 Appetite disturbance
 Sleep disturbances

22. Serotonin
 Nutritional building blocks
 Foods rich in tryptophan, an amino acid that
converts to serotonin in the brain.
Whole-wheat
Potatoes
Brown rice
Lentils
Oats
Beans

23. Serotonin
 Medications
 SSRIs
 SNRIs
 5-HTP
 SAM-e

24. Serotonin Age Related Changes
 Serotonin goes down when estrogen or
testosterone go down (Dr. Jacques Lorrain.
(1994) Comprehensive Management of
Menopause)
 Melatonin doesn’t decline as we age,
unless serotonin declines significantly
https://www.web
md.com/healthy-
aging/news/19991
105/melatonin-
levels-dont-
decline-with-
age#1

25. Acetylcholine
 Mechanism of action/purpose
 In lower amounts, ACh can act like a stimulant by
releasing norepinephrine (NE) and dopamine (DA)
 Memory
 Motivation
 Higher-order thought processes
 Sexual desire and activity
 Sleep

26. Acetylcholine
 Symptoms of excess
Depression (all symptoms)
Nightmares
Mental Fatigue
Anxiety
 Inverse relationship between serotonin and
acetylcholine

27. Acetylcholine
 Insufficiency
 Alzheimer’s/dementia
 Parkinson’s
 Impaired cognition, attention, and arousal

28. Acetylcholine
 Nutritional building blocks
 Foods high in choline
Meats
Dairy
Poultry
Chocolate
Peanut butter
Wheat germ
Brussels sprouts and broccoli

29. Acetylcholine
 Anticholinergic drugs are used to treat a
variety of conditions:
 Gastrointestinal disorders (e.g., gastritis, diarrhea,
diverticulitis, ulcerative colitis, nausea, and
vomiting)
 Genitourinary disorders (e.g., cystitis, urethritis,
prostatitis)
 Respiratory disorders (e.g., asthma, chronic
bronchitis, and chronic obstructive pulmonary
disease [COPD])
 Insomnia, although usually only on a short-term
basis.

30. Acetylcholine
 Medications
 Anticholinergics
Atropine
Benzatropine (Cogentin)
Chlorpheniramine (Chlor-Trimeton)
Dimenhydrinate (Dramamine)
Diphenhydramine (Benadryl, Sominex, Advil PM,
Unisom)
Hydroxyzine (Atarax, Vistaril)
Bupropion (Zyban, Wellbutrin)
Dextromethorphan - Cough suppressant
Alzheimer’s/dementia
Parkinson’s
Impaired cognition,
attention, and
arousal

31. Summary
 There are a variety of different
neurotransmitters involved in addiction and
mental health disorders
 It is not always about increasing a
neurotransmitter. Sometimes you need to
decrease it or increase another
neurotransmitter to facilitate it.
 Human brains try to maintain homeostasis and
too much or too little can be bad
 A balanced diet will provide the brain the
necessary nutrients in synergystic combinations

32. References
 Res Nurs Health. 2014 Jun;37(3):185-93. doi:
10.1002/nur.21595. Epub 2014 Apr 3. Neurobehavioral
effects of aspartame consumption.Lindseth GN1, Coolahan
SE, Petros TV, Lindseth PD.
 http://www.smithsonianmag.com/science-nature/could-diet-
soda-cause-clinical-depression-586801/?no-ist
 Understanding our Bodies: Dopamine and Its Rewards
http://nutritionwonderland.com/2009/07/understanding-
our-bodies-dopamine-rewards/
 http://nutritionwonderland.com/2009/06/understanding-
bodies-serotonin-connection-between-food-and-mood/

33. References
 Myo-inositol content of common foods:
development of a high-myo-inositol diet.
http://ajcn.nutrition.org/content/33/9/1954.
abstract
 Neuroscience. 2002;111(2):231-9. GABA
mechanisms and sleep. Gottesmann C.
 Biofactors. 2006;26(3):201-8. Relaxation and
immunity enhancement effects of gamma-
aminobutyric acid (GABA) administration in
humans. Abdou AM1, Higashiguchi S, Horie K,
Kim M, Hatta H, Yokogoshi H.

34. References
 Neuropsychopharmacology: The Fifth
Generation of Progress Editors: Kenneth
L. Davis et. Al. Publisher Lippincott,
Williams, & Wilkins, Philadelphia,
Pennsylvania, 2002
http://www.acnp.org/publications/neuro5
thgeneration.aspx