Flashcards in NEUR 0010 - Chapter 22 Deck (24):
What is the stress response?
Coordinated reactions to threatening stimuli: avoidance behavior, increased vigilance and arousal, activation of SANS, release of cortisol from adrenal glands
Where is cortisol released from? By what?
Released from the adrenal cortex in response to elevated blood ACTH levels
Where is ACTH released from? By what?
From the anterior pituitary in response to elevated blood CRH levels
Where is CRH released from? By what?
From the hypothalamus into the hypothalamo-pituitary portal circulation in response to parvocellular neurosecretory secretion in the paraventricular nucleus of the hypothalamus
What two structures regulate the CRH neurons in the hypothalamus?
Amygdala and hippocampus
What part of the amygdala activates the HPA axis?
The bed nucleus of the stria terminalis: collection of neurons in the amygdala
How does hippocampal activation affect CRH release?
Inhibits in (instead of promotes, like the amygdala); uses its glucocorticoid receptors to detect elevated cortisol levels and acts through negative feedback on the hypothalamus
What are the two major classes of anxiolytic drugs?
Benzodiazepines and SSRIs
How are benzodiazepines anxiolytic?
Act on inhibitory GABA receptors: make them open more easily and increase inhibition
How are SSRIs anxiolytic?
Allow serotonin to stay in the synaptic cleft longer, and somehow cause the nervous system to adapt to chronically elevated brain serotonin and increased hippocampal glucocorticoid receptors (enhancing negative feedback loop for elevated cortisol)
What is type I vs type II bipolar?
Type I is manic episodes alone; Type II is hypomanic and major depressive episodes
What is cyclothymia?
Cycling between hypomania and minor depressive episodes
What is the monoamine hypothesis of mood disorders?
Depression as a consequence of a deficit in one of the diffuse modulatory systems of monoamines (NE, 5HT)
Which two monoamines are associated with mood disorders?
Norepinephrine and serotonin
What is the diathesis-stress hypothesis of mood disorders?
That the HPA axis is the main site where genetic and environmental influences converge to cause mood disorders
What happens to the HPA axis during depression?
Highly active: elevated blood cortisol, elevated brain CRH
What are five successful drugs for mood disorders?
Tricyclics, SSRIs, NE-reuptake inhibitors, lithium, and MAOIs
How do tricyclics help treat depression?
Block NE and 5HT reuptake
How do MAOIs help treat depression?
Prevent degradation of NE and 5HT
How does lithium help treat bipolar?
Prevents normal PIP2 turnover (important in GPCRs) and interferes with adenylyl cyclase
What are some positive symptoms of schizophrenia?
Delusions, hallucinations, disorganized speech, grossly disorganized or catatonic behavior
What are some negative symptoms of schizophrenia?
Flat affect, poverty of speech, difficulty in initiating goal-directed behavior, memory impairment
What is the dopamine hypothesis of schizophrenia?
Psychotic episodes are triggered by activation of DA receptors