6

=Hypothalamic pituitary adrenal circuit

aim of the stress response is to provide energy for a long period of time

adrenal glands

1. stressed
2. hypothalamus secrets corticotropin

3. stimulates pituitary
4. produces adrenocorticotropic hormone (ACTH )
5. ACTH stimulates adrenal gland
6. production of cortisol
7. cortisol mobilises glucose stored in the liver, this provides a constant supply of energy
8. stress response : secretion of hormones called epinephrine and norepinephrine
9. hypothalamic are regulated by norepinephrine (locus coeruleus)

role of hippocampus is to inhibit hypothalamus

stress state the hippocampus is smaller, stress state larger

if hippocampus activity low = hypothalamus activity high = stress

: acquired and persistent syndrome of intellectual impairment ( majour/mind neurocognitive disorder NCD/mildNCD )

1. Altzimer's disease
2. Fronototemporal dementia (Pick)
3. Vascular dementia

most prevalent dementia (65%)

reduction in two or more transmitter system

ACh , noradrenaline , DA, 5HT , glutamate receptors

problems with neuritic plaques , paired helical filaments

cortex shrinks ans atrophies

lose 3rd of volume

1. posterior parietal cortex
2. inferioir temporal cortex
3. limbic cortex

the entorhinal cortex is not present

substantial reduction in large neurons (shrink rater than dissapear

loss of dentric arborization

hippocampal dentric arborization usually increases between 50 70

both Alzhimers and dementia have vascular porblems

cardiovascular risk factors → cerebrovascular changes → Leukoartrosis

diffuse white matter abnormalities

either due to untreated or hypertreated

small holes : reticular infarctions

result of accumulation of tau protein

found in cortex of patients with Alzhimer

structure : core of amyloid ( homogenous protein material)+ degerative cellular fragments

increase in concentration = magnitude of deterioration

outside cell ( neurons cannot communicate )

found in cerebral cortex and hippocampus

seen in both Alzimher down syndrome

posterior half of hippocampus affected more sevrly

also related to tau protein

double helical conficuration