| الوصف: |
Stress is an important factor in the etiology of mood disorders and addictive behaviors. Prenatally restraint stressed (PRS) rats, i.e. the offspring of dams submitted to repeated episodes of stress during the last ten days of gestation, display stress-related disorders (anxiety, depression, vulnerability to drugs of abuse), with a clear-cut sex effect in PRS-induced profile: PRS males are anxious while PRS rats of both sexes display a depressive-like behavior. An impairment of glutamate release in the ventral hippocampus lies at the core of the anxiety-like profile of PRS rats and we have shown that chronic treatment with antidepressants enhanced glutamate release and corrected PRS rats anxious-/depressive-like profile. Here, for the first time, the alteration of circadian patterns, as a feature of depression, was analyzed both in male and female rats. We have shown a gender-specific outcome of PRS on circadian patterns of locomotor activity, resynchronization to a new light-dark cycle, and hypothalamic CRH levels. We extended the impact of sex in our model to addiction and demonstrated that 1)sex hormones play a key role in determining rats preference for drugs in a conditioned place preference paradigm; 2)sensitiveness is stimulus-dependent (natural reward chocolate vs cocaine). Finally, we found that an enhanced preference for cocaine, shown in females and in PRS rats of both sexes, was linked to the locomotor activating effect of the drug but also to its anxiolytic and antidepressant effect. This suggests that preference for a drug is increased when the drug is able to correct mood disorders, reinforcing the hypothesis of self-medication in addiction. ; Le stress est un facteur d’importance dans l'étiologie des troubles de l'humeur et de l’addiction. Des rats stressés prénatalement (SPN), i.e. la progéniture de femelles soumises à des épisodes répétés de stress les 10 derniers jours de gestation, présentent des troubles liés au stress (anxiété, dépression, vulnérabilité aux drogues), avec un effet net du ... |
