Enriched environment reverses the despair behaviour the decrease in light neurofilament and synaptic markers in rat hippocampus

SIFONIOS L; TRINCHERO MF; REIN¨¦S A; CERESETO M; FERRERO A; WIKINSKI S

San Antonio

Congreso; 39th Annual American Society for Neurochemistry MEETING; 2008

American Society for Neurochemistry

This work investigated the potential effect of enriched environment (EE) on the behavioral impairment in animals exposed to the learned helplessness (LH) paradigm and on three neuronal markers found decreased in LH rats. Male rats, in which LH behavior was induced, were kept in the EE, a special cage provided with different devices (LHEE). LH animals housed in standard cages were the control group (LH). A group of animals not exposed to LH paradigm was employed (C). Depressive-like behavior (escape latency, EL, in an active task) was measured 21 days later. LHEE animals showed reversion of the behavioral despair in comparison with the LH group. Quantification of the NFL immunoreactive area was performed in the dentate gyrus (DG) and in the CA3 of the hippocampus. LHEE group exhibited a significant increase in the relative immunoreactive area in comparison with the LH group in DG. In CA3 LHEE displayed no differences either with LH or C group. In a double immunofluorescence BrdU/Beta Tubulin III, no increment in the neuronal survival was observed in the LHEE. Both SYN and PSD labeling were significantly decreased in LH animals in comparison with C ones. In the LHEE there was a partial reversion in SYN and a complete reversion in PSD labeling. The EE induces an antidepressant-like effect and exerts a beneficial structural action on NFL, SYN and PSD in animals exposed to an experimental model of depression. These changes seem not to be due to an increment in the neuronal survival.