CSB332H1 Lecture Notes - Lecture 1: Prefrontal Cortex, Locus Coeruleus, Pyramidal Cell
14 May 2018
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Figure 1.0
Lecture 1(a): Synapse Overview
Neurobiology of Stress:
• Stress directly affects the brain, being processed in
the cerebral cortex
o Stress affects different structures in the brain
(or immune system) directly or indirectly
§ Stress is handled as a unique
physiological response
ð Anterior Cingulate; important how we mediate stress
• Stress is not always harmful, short-term stress (writing an exam) is processed in the cerebral
cortex and will act on the locus coeruleus to cause the release of norepinephrine (NE)
o NE is beneficial as it enhances vision and processes sensory signals more efficiently
• Prolonged or excessive stress is harmful, lead to the release of higher levels of
glucocorticoids which function to affect neurons and their synapses in the brain
Animal Models of Stress:
Figure 1.0
• Physical stress (immobilization, via immobilization bag or
restrainer) applied on an animal acutely (1 day) or prolong
(few days)
o Outcome of the brain at the end of the stress period
is incredibly different
• Two different forms of stress:
o Acute – beneficial
o Chronic – detrimental
ð Various forms of stress and duration of stress on different
animals cause changes in the synapses, the neurons in various
areas of the brain, their circuits and behavior
o Physical stress – immobilization
o Psychosocial stress – predator odor, maternal separation
Stress Affects Multiple Brain Areas:
• Different areas of the brain are affected by stress yielding variable responses
o Amygdala => spiny neurons
o Nucleus Accumbens => medium spiny neurons
o Ventral Tegmental Area (VTA) => dopamine neurons
o Substantia Nigra (SNr) => dopamine neurons
o Hippocampus => CA3 pyramidal neuron
o Medial prefrontal cortex => pyramidal neuron
ð Will the same neurons (pyramidal, spiny) respond the
same way when found in different areas?
Document Summary
Neurobiology of stress: stress directly affects the brain, being processed in the cerebral cortex, stress affects different structures in the brain (or immune system) directly or indirectly. Stress is handled as a unique physiological response. Prolonged or excessive stress is harmful, lead to the release of higher levels of glucocorticoids which function to affect neurons and their synapses in the brain. Stress affects multiple brain areas: different areas of the brain are affected by stress yielding variable responses. Figure 1. 0: amygdala => spiny neurons, nucleus accumbens => medium spiny neurons, ventral tegmental area (vta) => dopamine neurons, substantia nigra (snr) => dopamine neurons, hippocampus => ca3 pyramidal neuron, medial prefrontal cortex => pyramidal neuron. Effects of stress on morphology & function of neurons: amygdala, spiny neuron: Function - encodes for fear and anxiety related memory: pathophysiology (w/ stress): Hyperarousal and exaggerated startle: nucleus accumbens, medium spiny neuron:
