Single intense prenatal stress reduce behavioural suppression in an operant conflict paradigm in the adult progeny. Influence of Metyrapone administration

Stressors presented during late prenatal period can have long-term effects on offspring behaviour (1). Indeed we showed that in the rat progeny a single immobilization procedure at gestational day 16 enhances spatial learning in a non-aversive, rewarded-facilitated learning task, the Can Test, and decreases anxiety-like behaviour in the elevated plus maze (2). In this study, we wanted to investigate: (i) the effects of a single prenatal immobilization-stress on the operant conflict task (OCT), an anxiety-related procedure, in which positively reinforced responses are suppressed by contingent punishment (3); (ii) the expression of mineralcorticoid and glucocorticoid receptors (MRs, GRs) in t…

Pregnenolone sulphate (PREGS) affects spatial learning and memory in two different cognitive tasks in adult rats. Influence of the emotional state.

Pregnenolone sulphate (PREGS) is one of the most potent memory-enhancing neurosteroids in rodent learning studies, also involved in the modulation of the emotional state (Valleè et al 2001). Neurosteroids exert an important role as modulators of the neuronal activity by interacting with different receptors or ion channels (Urani et al 1998). Indeed PREGS acts as negative modulator of GABAA- and as positive modulator of NMDA -receptors. Altered levels of PREGS have also been reported during aging and in human neurodegenerative pathologies like Alzheimer’s disease. The aim of this study was to investigate, in adult male rats, the effects of a single injection of PREGS (10 mg/kg s.c.) on: i) o…

Single intense prenatal stress can differently affect emotional behavior according to the nature of the task. Influence of metyrapone