Enriched environment prevents the diminution of PSD-95 and a cell adhesion molecule and produces a plastic effect through the increase of MAP2 and neurexin in animals exposed to an experimental model of depression

L. SIFONIOS; MA. L. CLADOUCHOS; G. FERNÁNDEZ MACEDO; S. WIKINSKI

Huerta Grande, Córdoba, Argentina

Congreso; I Reunión Conjunta de Neurociencias (IRCN); 2009

Sociedad Argentina de Neurociencia y Taller de Neurociencia

In a previous work we demonstrated that 21 days of enriched environment (EE) produced the reversion of the depressive-like behavior and of  the diminution of both the light subunit of neurofilament and the postsynaptic density 95 (PSD-95) in rats exposed to an experimental model of depression, the learned helplessness (LH). In order to elucidate which mechanisms are involved in the reversion of these proteins, we analyzed the immunoreactive area of neuroligin (NLG), which interacts with PSD-95, and neurexin (NRX). Both NLG and NRX are cell adhesion molecules involved in the synaptogenesis. NLG anchors PSD-95 and produced its activation, therefore leading to a presynaptic activation by binding to NRX. The measurement of NLG and NRX after 10 and 21 days of enrichment showed that EE increased NRX immunoreactivity and that it prevented the diminution of NLG observed in LH animals housed in standard cages. A similar result than that was found in PSD-95 immunoreactivity. Besides, MAP2, a marker of dendritic differentiation, was increased in stressed animals housed in the EE (LHEE group). All these results suggest that the EE produces differential effects on the proteins studied and that induces plastic actions in animals exposed to the LH paradigm. Supporting grants: ANPCyT PICT-2005-31953, UBA M073.