Prenatal resident-intruder stress decreases levels of allopregnanolone in the cortex, hypothalamus, and midbrain of males, and increases levels in the hippocampus and cerebellum of female, juvenile rat offspring

Abstract

Prenatal stress (PNS) can influence behaviors associated with cognition, reward and emotional regulation, which are controlled by brain areas such as the cortex, hippocampus, hypothalamus, midbrain and cerebellum. Allopregnanolone in these regions modulates behavioral and parasympathetic effects. The current study tested whether exposing pregnant dams to 5 days of resident-intruder stress on prenatal days 15-20 for 10 min altered the levels of allopregnanolone in cortex, hypothalamus, hippocampus, midbrain, and cerebellum of male and female juvenile offspring. In cortex, hypothalamus, and midbrain of male rats exposed to prenatal stress, levels of allopregnanolone were significantly lower compared to all other groups. In the hippocampus and cerebellum, among females exposed to prenatal stress levels were significantly higher compared to all other groups. These differences in allopregnanolone levels varying by prenatal stress, sex and brain regions provide insight in potential mechanism of stress regulation and etiopathophysiology of stress-related disorders.

Keywords: Chronic stress; Corticosterone; Dopamine; Microdialysis; Rat; Spatial memory.

Fig. 1

There was a significant interaction between sex and PRENATAL STRESS. Male juvenile offspring whose dams had been exposed to stress (grey bars) had significantly lower levels of allopregnanolone in cortex, compared to male offspring of control dams (black bars), prenatal stress female rats (grey diagonal bars), and female control rats (black vertical stripes).

Fig. 2

There was a significant interaction between sex and PRENATAL STRESS. Male juvenile offspring whose dams had been exposed to stress (grey bars) had significantly lower levels of allopregnanolone in cortex, compared to male offspring of control dams (black bars), prenatal stress female rats (grey diagonal bars) and female control rats (black vertical stripes).

Fig. 3

There was a significant interaction between sex and PRENATAL STRESS. Male juvenile offspring whose dams had been exposed to stress (grey bars) had significantly lower levels of allopregnanolone in midbrain, compared to male offspring of control dams (black bars), prenatal stress female rats (grey diagonal bars) and female control rats (black vertical stripes).

Fig. 4

There was a significant interaction between sex and PRENATAL STRESS. Prenatal stress females (grey diagonal bars) had significantly higher levels of allopregnanolone in hippocampus compared to female control rats (black vertical stripes), male juvenile offspring of control dams (black bars), and those whose dams had been exposed to stress (grey bars).

Fig. 5

There was a significant interaction between sex and PRENATAL STRESS. Prenatal stress females (grey diagonal bars) had significantly higher levels of allopregnanolone in cerebellum compared to female control rats (black vertical stripes), male juvenile offspring of control dams (black bars), and those whose dams had been exposed to stress (grey bars).