Abstract
Stress, including prenatal maternal stress, increases affective disorder morbidity. Furthermore, women appear twice as likely as men to develop stress- and depression-related disorders. Some of the behaviors associated with depression are also found in rat offspring following maternal prenatal stress (PS) incl. increased helplessness and altered anxiety response. Our purpose was to investigate behavioral depression indices following PS and potential differences between male and female offspring.
To this end, pregnant Sprague-Dawley rats were subjected to repeated variable stress on days 13-21 of gestation. The PS paradigm consisted of short-term stressors during the day (e.g. restraint, forced swimming, elevated platform placement) and a long-term stressor during the night (e.g. fasting, lights on). At post natal day 50-70, motor activity, depressive-like (forced swim test), anxiety-like (elevated plus maze, EPM), and sleep behavior (via EEG recordings) was assessed in male and female offspring. In addition, half of PS and control animals, respectively, were exposed to an acute stressor prior to the behavioral tests.
Weight gain during the last part of the pregnancy was significantly reduced in dams exposed to PS. Locomotor activity in a familiar environment (housing cage) during the rodent inactive phase was significantly enhanced in PS females compared to controls (Δ= 49 %, n = 15-37; p < 0.001). In contrast, PS decreased locomotor activity in male offspring during the rodent active phase (Δ= 18%, n = 11-33, p = 0.04), indicating that PS induces sex-specific behavioral changes. In the EPM, PS per se did not appear to change behavior in either sex. Exposure to an acute stressor, however, increased the amount of time spent in the open arm specifically in control males (Δ= 82%, n = 13-15; p < 0.001), and, interestingly, PS appeared to blunt this reaction (Δ= 21%, n = 5-6; p < 0.36). In summary, PS induces sex-specific behavioral changes where female offspring appears more vulnerable in a familiar environment whereas male offspring seems vulnerable in a novel environment. The central mechanisms mediating these differences may also contribute to sex-specific sensitivity to stressors and depression propensity in humans.
To this end, pregnant Sprague-Dawley rats were subjected to repeated variable stress on days 13-21 of gestation. The PS paradigm consisted of short-term stressors during the day (e.g. restraint, forced swimming, elevated platform placement) and a long-term stressor during the night (e.g. fasting, lights on). At post natal day 50-70, motor activity, depressive-like (forced swim test), anxiety-like (elevated plus maze, EPM), and sleep behavior (via EEG recordings) was assessed in male and female offspring. In addition, half of PS and control animals, respectively, were exposed to an acute stressor prior to the behavioral tests.
Weight gain during the last part of the pregnancy was significantly reduced in dams exposed to PS. Locomotor activity in a familiar environment (housing cage) during the rodent inactive phase was significantly enhanced in PS females compared to controls (Δ= 49 %, n = 15-37; p < 0.001). In contrast, PS decreased locomotor activity in male offspring during the rodent active phase (Δ= 18%, n = 11-33, p = 0.04), indicating that PS induces sex-specific behavioral changes. In the EPM, PS per se did not appear to change behavior in either sex. Exposure to an acute stressor, however, increased the amount of time spent in the open arm specifically in control males (Δ= 82%, n = 13-15; p < 0.001), and, interestingly, PS appeared to blunt this reaction (Δ= 21%, n = 5-6; p < 0.36). In summary, PS induces sex-specific behavioral changes where female offspring appears more vulnerable in a familiar environment whereas male offspring seems vulnerable in a novel environment. The central mechanisms mediating these differences may also contribute to sex-specific sensitivity to stressors and depression propensity in humans.
| Originalsprog | Engelsk |
|---|---|
| Publikationsdato | 2013 |
| Status | Udgivet - 2013 |
| Begivenhed | Society for Neuroscience Annual Meeting - San Diego, CA, USA Varighed: 9 nov. 2013 → 14 nov. 2013 |
Konference
| Konference | Society for Neuroscience Annual Meeting |
|---|---|
| Land/Område | USA |
| By | San Diego, CA |
| Periode | 09/11/2013 → 14/11/2013 |