TABLE 1. Comparing HPA Profiles in Aged
Rats and Depressed Humans
|
|
Aging |
Chronic stress |
Major depression |
|
Hippocampal GR/MR |
|
- |
? |
|
Hypothalamic CRH mRNA |
- |
|
? |
|
Hypothalamic CRH secretion |
|
- |
|
|
CRH pituitary responsiveness |
|
|
|
|
Peripheral cort. levels at
rest |
Unchanged or elevated at nadir |
Unchanged or elevated at nadir |
Unchanged or elevated at nadir
|
|
Drive (metyrapone test) |
? |
? |
|
|
Cort. levels following stress |
Delayed turn off to some stressors |
- |
? |
|
Fast-feedback |
|
|
|
|
Dexamethasone feedback |
|
|
|
|
Pituitary POMC mRNA |
Decreased but increased translatability |
|
|
shows
an increase, 
shows a decrease,
- indicates no change, ? indicates unknown effect.