There has been an increasing importance of studies that link sex to stress coping processes. Recently, we reported that male and female Wistar rats responded differently to prenatal stress (PS) under basal conditions....There has been an increasing importance of studies that link sex to stress coping processes. Recently, we reported that male and female Wistar rats responded differently to prenatal stress (PS) under basal conditions. The aim of the present study was to determine the influence of sex on behaviour and coping strategies, as an effect of gestational adversity in rats that were exposed to an uncontrollable stressor. Once the animals reached adulthood, the offspring from stressed/non-stressed dams were subjected or not to antidepressant treatment with Sertraline. After that, they were exposed to a single inescapable shock (IS) session, in which the rats were further tested for escape behaviour along 10 days, as a model of learned helplessness (LH). In prenatally stressed animals after the IS, behavioural differences appeared in a sex specific manner. Males proved to be more susceptible to the adverse context than females, exhibiting behavioural despair in a large percentage of the cases. Surprisingly, PS did not affect shock escape failure, but did affect learning performance in a sex dependent manner. In females, PS led them to learn to avoid shocks, learning better than controls, and by contrast, PS males did not learn to avoid shocks and displayed some signs of anhedonia. Sertraline did not help animals to avoid shocks, but helped them to escape from it. Our data indicate the existence of sex dependent behavioural differences in PS animals when facing an uncontrollable stress situation, in which the changes induced by PS were not only different, but opposite between sexes.展开更多
The serotonergic system in the brain plays a major role in mood and anxiety regulation when exposed to stress. The aim of the present study was to evaluate the effects of Sertraline administration in coping with stres...The serotonergic system in the brain plays a major role in mood and anxiety regulation when exposed to stress. The aim of the present study was to evaluate the effects of Sertraline administration in coping with stress using the behavioural paradigms of the acoustic startle reflex (ASR) and its prepulse inhibition (PPI) in both sexes. Wistar rats were divided into two groups: intact animals and exposed to restraint stress (RS) 3 times per day during 7 days, which were then subdivided into three other groups: injected with Sertraline (5 mg/kg/day) or the drug vehicle saline for 8 consecutive days, and non-injected. ASR and PPI values were analyzed along 4 sessions to determine behavioral changes. Upon it, we also determine the effects of acute immobilization stress analyzing physiological stress indicators in blood. Our data show sex differences in response to stress paradigms. RS affected more intensely males than females, disturbing the males’ growth and the long-term startle habituation that were not affected in females. PPI increased in the vehicle-injected animals when compared to baseline in both sexes, and Sertraline reversed more efficiently it in females. Moreover, despite both sexes exposed to stressful paradigms exhibited a significant increase in serum glutamic-oxaloacetic transaminase and lactate dehydrogenase enzymes when compared with intact controls, as well as leucopenia, some differences according to sex were found in the haemostatic response to stress. Notably, the repeated injections procedure disturbed the early response to stress, which Sertraline only attenuated in both sexes. Our data suggest that 8-day Sertraline administration is effective in reversing stress-induced changes in some physio-logical parameters, but insufficient to return immunological values to normality.展开更多
文摘There has been an increasing importance of studies that link sex to stress coping processes. Recently, we reported that male and female Wistar rats responded differently to prenatal stress (PS) under basal conditions. The aim of the present study was to determine the influence of sex on behaviour and coping strategies, as an effect of gestational adversity in rats that were exposed to an uncontrollable stressor. Once the animals reached adulthood, the offspring from stressed/non-stressed dams were subjected or not to antidepressant treatment with Sertraline. After that, they were exposed to a single inescapable shock (IS) session, in which the rats were further tested for escape behaviour along 10 days, as a model of learned helplessness (LH). In prenatally stressed animals after the IS, behavioural differences appeared in a sex specific manner. Males proved to be more susceptible to the adverse context than females, exhibiting behavioural despair in a large percentage of the cases. Surprisingly, PS did not affect shock escape failure, but did affect learning performance in a sex dependent manner. In females, PS led them to learn to avoid shocks, learning better than controls, and by contrast, PS males did not learn to avoid shocks and displayed some signs of anhedonia. Sertraline did not help animals to avoid shocks, but helped them to escape from it. Our data indicate the existence of sex dependent behavioural differences in PS animals when facing an uncontrollable stress situation, in which the changes induced by PS were not only different, but opposite between sexes.
基金supported by the University of Salamanca Research Support Grant 2015 to Dr.Dolores E.Lopez
文摘The serotonergic system in the brain plays a major role in mood and anxiety regulation when exposed to stress. The aim of the present study was to evaluate the effects of Sertraline administration in coping with stress using the behavioural paradigms of the acoustic startle reflex (ASR) and its prepulse inhibition (PPI) in both sexes. Wistar rats were divided into two groups: intact animals and exposed to restraint stress (RS) 3 times per day during 7 days, which were then subdivided into three other groups: injected with Sertraline (5 mg/kg/day) or the drug vehicle saline for 8 consecutive days, and non-injected. ASR and PPI values were analyzed along 4 sessions to determine behavioral changes. Upon it, we also determine the effects of acute immobilization stress analyzing physiological stress indicators in blood. Our data show sex differences in response to stress paradigms. RS affected more intensely males than females, disturbing the males’ growth and the long-term startle habituation that were not affected in females. PPI increased in the vehicle-injected animals when compared to baseline in both sexes, and Sertraline reversed more efficiently it in females. Moreover, despite both sexes exposed to stressful paradigms exhibited a significant increase in serum glutamic-oxaloacetic transaminase and lactate dehydrogenase enzymes when compared with intact controls, as well as leucopenia, some differences according to sex were found in the haemostatic response to stress. Notably, the repeated injections procedure disturbed the early response to stress, which Sertraline only attenuated in both sexes. Our data suggest that 8-day Sertraline administration is effective in reversing stress-induced changes in some physio-logical parameters, but insufficient to return immunological values to normality.
