Neuroendocrinology

Question 1

What are the short term consequences of stress?

Answer 1

Effect on brain function ->
adaptation to environment

Question 2

What are the consequences of long term stress?

Answer 2

Adaptation ->
Psychiatric disorders

Question 3

How do the nervous system and endocrine system interact?

Answer 3

Neurotransmitters
Hormones

Question 4

How do the immune system and endocrine system interact?

Answer 4

Cytokines
Hormones

Question 5

How do the nervous system and immune system interact?

Answer 5

Neurotransmitters
Cytokines

Question 6

What parts of the CNS are in the endocrine system?

Answer 6

Pineal gland
Hypothalamus
Pituitary gland

Question 7

What are the pituitary hormones? What are their target organs?

Answer 7

TSH (thyroid)
ACTH (adrenal cortex)
FSH and LH (testes/ovaries)
Growth hormone (entire body)
Prolactin (mammary glands)
Endorphins (brain- pain receptors)

Question 8

How do the endocrine and nervous system influence each other?

Answer 8

All hormones affect brain activity
Almost all endocrine secretions are controlled by the brain

Question 9

What are the psychiatric symptoms of Cushing’s syndrome?

Answer 9

Depression
Irritability
Loss of recent memory

Question 10

How does mineralocorticoid receptor respond to corticosterone and cortisol?

Answer 10

Binds with high affinity to regulate circadian fluctuation of these hormones

Question 11

How does glucocorticoid receptor respond to corticosterone and cortisol?

Answer 11

Binds with low affinity
Takes a higher level of hormones to initiate response
Regulates response in times of stress, when levels are high

Question 12

What gets is used when cortisol overproduction is suspected?

Answer 12

Dexamethasone to suporeee cortisol levels

Low dose will differentiate healthy from people producing too much

High dose will differentiate Cushing’s disease

Question 13

How does the HPA axis regulate stress response?

Answer 13

Stress stimulates hypothalamus to release CRF
CRF stimulates the anterior pituitary to produce ACTH
ACTH stimulates the adrenal glands to produce cortisol
Cortisol stimulates physiological changes (fight or flight) and sends inhibitory signals to hypothalamus and pituitary

Question 14

What happens when cortisol activates the glucocorticoid receptor?

Answer 14

Receptor released HSP complex and translocated into the nucleus

There the GR regulates gene transcription to initiate physiological changes

Question 15

How is the HPA axis disrupted in patients with depression?

Answer 15

Glucocorticoid receptors are resistant to

Translocation and downstream effects cannot happen

Negative feedback is disrupted and glucocorticoid levels remain high

Question 16

How does stress affect neuroplasticity?

Answer 16

Shortens dendrites
Effect is reversible over weeks

Effect seems to be mediated by the HPA axis (cortisol)

Question 17

What evidence points to elevated disrupted HPA axis in depression and psychosis?

Answer 17

Enlarged pituitary gland
Cortisol hypersecretion
Dexamethasone non suppression

Question 18

How does high glucocorticoid induce psychosis?

Answer 18

Glucocorticoids increase dopaminergic activity in the mesolimbic pathway

Question 19

How does cortisol correlate with hippocampal volume in psychosis?

Answer 19

Negative correlation
Higher cortisol = smaller hippocampal volume

Question 20

How do patients with psychosis differ from patients with depression I. Response to stress?

Answer 20

Patients with psychosis do not mount a stress response to social stress tests, patients with depression do

Question 21

What biomarker might be useful for predicting non-response to psychosis treatment?

Answer 21

Awakening cortisol response

Question 22

What biomarkers support the theory of higher inflammation in depression and psychosis?

Answer 22

Higher cytokine levels (TNF, IL6) preceding the onset of depression

Question 23

How does childhood trauma affect inflammation levels?

Answer 23

Higher levels of inflammatory markers even with disorder group

Question 24

Has anti inflammatory treatment proved useful in all patients with depression?

Answer 24

No, only in higher levels inflammation
Low level inflammation might be neuro protective

Question 25

How is the HPA axis involved in inflammation?

Answer 25

CRF activated the locus coeruleus to activate the sympathetic nervous system

This stimulates release of cytokines

Cytokines alter monoamine metabolism, increase excitotoxicity, decrease trophic factor (BDNF) production