Presentation on Neuroscience of Stress

1. Neuroscience of Stress
Dr.Suresh Kumar Murugesan PhD and Ms.Jothi
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2. About us
● Dr.Suresh Kumar Murugesan Phd and
Ms.Jothi are the founders of Yellow Pond
counselling Centre
● They are positive psychologist striving for
the excellence in ethir field
● Both had acted as resource persons for many
training and webinars
● They are also life members of Tamil Nadu
Career Counsellors Association and Tamil
nadu Counsellors and Psychotherapist
Association
● They have developed few Psychometric tools
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3. Disclaimer
● This presentation is prepared
for learning purpose only and
anyone can use the content.
● All the images used in this
presentation are taken from
google image search.
● Due acknowledgement was
given to all the material
collected from the various
sources.
● Any name or reference is not
included kindly bring it to the
notice of the presenter for
inclusion.
● Email -
sureshkumar800@yahoo.com
Thank you
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4. Neurosceince
Neuroscience is scientific study of structure and function of the brain and neuron
It also studies the impact of brain on behavior and cognitive functions, or how
people think.
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5. What is stress?
Stress is the feeling of being overwhelmed or unable to cope with mental or
emotional pressure.
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8. Impact of Stress
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9. Stress and
Human Survival
Short-term stress evolved to help humans survive.
It triggers that powerful ‘fight or flight’ instinct that makes us
respond quickly when we’re in danger – and without it, our
ancestors wouldn’t have lasted long.
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10. Stress impairs Memory
● One effect of chronic stress that researchers have
observed is memory impairment.
● Specifically, it has been noted that people who are
stressed tend to be more forgetful and less likely to
remember specific information.
● Researchers believe that even minor stress, such as
being late to work, can cause to forget simple things
like where our keys are.
● One study performed on older rats even noted that
high levels of cortisol caused short-term memory
declines.
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11. Changes the Brain’s
Structure
● Our brain is composed of both gray matter and
white matter.
● Gray matter is used for decision-making and
problem-solving, while white matter is used to
connect regions of the brain and communicate
information.
● It has been noted that during times of chronic
stress, the myelin sheaths that make up white
matter become overproduced, while less gray
matter is produced.
● When this happens, there can be an imbalance in
gray and white matter. In some cases, this results
in permanent changes to the brain’s structure.
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12. Stress and Mental Illness
● An imbalance between white and gray matter can
also play a role in the development of mental illness.
● The theory is that having excess myelin in certain
areas of the brain interferes with the timing and
balance of communication.
● It was also noted that chronic stress can negatively
alter hippocampal function.
● The hippocampus is involved in memory, specifically
spatial memory, memory consolidation, and memory
transfer.
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13. Stress Kills Brain Cells
● It has been suggested by researchers that chronic
stress can even kill new neurons in the brain’s
hippocampus.
● The hippocampus is one of only two locations where
neurons are produced.
● Despite the fact that the formation of new neurons
does not seem to be affected, research shows that
new neurons produced during periods of stress are
more likely to die within a week.
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14. Stress Shrinks the Brain
While the overall volume of the brain tends to remain
about the same, it has been found that chronic stress in
otherwise healthy individuals can cause areas of the brain
associated with emotions, metabolism, and memory to
shrink.
Chronic stress also made people more likely to experience
brain shrinkage when exposed to intense stressors. This
means that people under constant stress may find it
harder to deal with future stress.
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15. Improves Cognitive
Function
● Stress is not all bad for our brain. In fact, moderate
stress can actually improve brain performance by
strengthening the connection between neurons in
the brain.
● This helps to improve memory and attention span in
order to make you more productive overall.
● This is why some people tend to perform “better
under pressure”.
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16. Stress and Brain Areas
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17. Prefrontal cortex
Stress can shrink the prefrontal cortex
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18. Amygdala
Stress can increase the size of
the amygdala
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22. Neurotransmitters
and Stress
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23. Catecholamines
Catecholamines are an
important part of the
body's stress response,
which can be vital in a
fight-or-flight response
to a perceived threat.
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24. Catecholamines
Catecholamines include
neurotransmitters such
as dopamine,
epinephrine
(adrenaline) and
norepinephrine
(noradrenaline), which
are released during the
body's stress response.
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27. Gamma-aminobutyric acid
● It is an important inhibitory neurotransmitter in the central nervous system.
● The role of GABA and benzodiazepine receptors has been well documented in stress disorders such as
anxiety, epilepsy, insomnia, and convulsive disorders.
● Stress has been reported to alter the content of the GABA neurotransmission, which suggests the
involvement of GABA in stress-induced behavioral and biochemical alterations.
● Melatonin (N-acetyl-5-methoxy-tryptamine) is a secretory product primarily synthesized in the pineal
gland and released into the bloodstream and cerebrospinal fluid.
● Study revealed the involvement of GABAergic mechanism in the hypnotic action of melatonin.[20]
Stress induces the release of CRF and GABA from the amygdala and hypothalamus.[21]
● It down-regulates vesicular glutamate transporter and its coupling with GABA-synthesizing enzyme,
glutamic acid decarboxylase (GAD65) in response to maternal separation could lead to decreased
GABA levels in the hippocampus.[22]
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28. Dopamine ● Stress-induced changes in dopamine (DA) levels within
terminal areas seem to involve mainly ventral tegmental
area projecting cells.
● Findings from preclinical studies suggest an uneven
response of DA in different stressful stimuli.
● Specifically, an acute and controllable/escapable
physical stress was seen to cause an enhanced DA
efflux in the ventral striatum, whereas chronic and
uncontrollable/inescapable exposure to the same stress
attenuated DA release.
● Parkinson's disease is an age-associated
neurodegenerative disease, clinically characterized as a
movement disorder arising due to selective
degeneration of dopaminergic neurons in the substantia
nigra of the ventral midbrain, thereby depleting the
dopamine levels in the striatum.
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29. Norepinephrine
● Brain epinephrine serves globally as an alarm system that decreases neurovegetative functions, such as
eating and sleeping, and this contributes to accompanying increase in autonomic and neuroendocrine
responses to stress, including HPA axis activation.[23]
● NE also activates the amygdala, the principal brain locus for fear-related behaviors, and enhances the
long-term storage of aversively charged emotional memories in sites such as the hippocampus and
striatum. Monoaminergic systems regulate the activity of neurons in the amygdala.[24]
● Stress has been reported to increase the turnover of NE in many terminal projection areas of the locus
ceruleus[25] and also increase extracellular NE in the hippocampus.
● There are substantial evidences suggesting that neurons in the brain containing and secreting
noradrenaline and CRF are activated during stress.[26] Hence, it is quite evident that both
noradrenaline and CRF are involved in behavioral responses to stress
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30. Serotonin ● Previous reports have suggested that stress affects the
activity of central dopaminergic and serotonergic
neurons.[29,30] Interactions between serotonin and
CRF have been demonstrated by various studies in
different parts of the brain.
● Studies have proved that significant reduction in
serotonin level increases the responsiveness to
stress.[31,32]
● Hippocampal serotonin concentrations are increased
during psychosocial conflict in animals.[33]
● The 5-hydroxytryptamine receptor 1A (5-HT1A)
receptors are down-regulated in distinct brain regions
including the hippocampus and cortex following stress
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31. Melatonin ● It is synthesized from tryptophan within the pinealocytes.
● Most synthetic activity occurs during the dark phase,
with a major increase (7-150 fold) in the activity of
serotonin-N-acetyltransferase.[35]
● Melatonin, being an endogenous hormone, has also
been known to improve the quality of sleep and reduce
the formation of free radicals; it also allows the
restoration of antioxidant enzymes.[36]
● Serotonin is the intermediate product in melatonin
synthesis and in the presence of serotonin-N-
transferase it gets converted into N-acetyl serotonin,
which further with the help of hydroxyl indole o-methyl
transferase gets converted into melatonin [Figure 3].
Thus, there is possibility of the involvement of
serotonergic neurotransmission in the protective effects
of melatonin.
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32. Glutamate ● There is substantial evidence indicating that the
Paraventricular nucleus (PVN) receives glutaminergic
innervations from large brain areas involving the PVN
itself and several other nuclei in and outside the
hypothalamus.
● Among the neuroanatomical regions of glutamatergic
afferents to the PVN, dorsomedial hypothalamic nucleus
is the candidate locus for glutamatergic neurons that
could be activated by immobilization stress.
● Microinjection of N-methyl-D-aspartate (NMDA) into the
dorsomedial hypothalamic nucleus causes an increase
in glutamate release in the PVN and results in
cardiovascular response very similar to the one evoked
by emotional stress
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33. References
1. Yvette Brazier (June 26, 2018). What is neuroscience?https://www.medicalnewstoday.com/articles/248680
2. https://www.jandsvision.com/blog/neuroscience-and-stress/
3. Godoy LD, Rossignoli MT, Delfino-Pereira P, Garcia-Cairasco N and Umeoka EHL (2018) A Comprehensive Overview on Stress
Neurobiology: Basic Concepts and Clinical Implications. Front. Behav. Neurosci. 12:127. doi: 10.3389/fnbeh.2018.00127
https://www.frontiersin.org/articles/10.3389/fnbeh.2018.00127/full
4. https://reader.elsevier.com/reader/sd/pii/S277252862100011X?token=83337A51CAFF12267A988170E0EE619C4850CBE4D22CE11F9260
9C958D875377DB8B06C2F00414266A6E370621368913&originRegion=eu-west-1&originCreation=20220611080958
5. https://journals.physiology.org/doi/full/10.1152/physrev.00041.2006
6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3697199/#ref2
7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6043787/
8. https://www.verywellmind.com/surprising-ways-that-stress-affects-your-brain-2795040
9. https://letstalkscience.ca/educational-resources/backgrounders/stress-and-brain
10. https://www.verywellmind.com/all-about-catecholamines-3145098
11. Elizabeth Scott, PhD (July 02, 2021) All About Catecholamines in the Stress Response. https://www.verywellmind.com/all-about-
catecholamines-3145098#
12. Kumar, A., Rinwa, P., Kaur, G., & Machawal, L. (2013). Stress: Neurobiology, consequences and management. Journal of pharmacy &
bioallied sciences, 5(2), 91–97. https://doi.org/10.4103/0975-7406.111818
13. Yaribeygi, H., Panahi, Y., Sahraei, H., Johnston, T. P., & Sahebkar, A. (2017). The impact of stress on body function: A review. EXCLI
journal, 16, 1057–1072. https://doi.org/10.17179/excli2017-480
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