Transient changes in GluN1 and GluN2A NDMAR subunits expression after habituation

MAGALÍ C CERCATO; CECILIA A VÁZQUEZ; EDGAR KORNISIUK; ALEJANDRA AGUIRRE; MARINA SNITCOFSKY; MA. VERÓNICA BÁEZ; DIANA JERUSALINSKY

Mar del Plata

Congreso; XXX Annual Meeting and SAN-ISN Small Conference and Course; 2015

Sociedad Argentina de Investigación en Neurociencias

NMDA receptors (NMDAR) play a critical role in synaptic plasticity, are required formemory encoding and ?storage? (Paoletti et al., 2013). NMDAR are heterotetramerscomposed by 2 GluN1 obligatory subunits and 2 regulatory subunits, being GluN2A andGluN2B the major regulatory subunits in CNS regions involved in cognitive functions. Wehave shown that about 1 hour after memory acquisition of a hippocampus depending task(open field [OF] habituation, GluN1 and GluN2A expression transiently increased in thehippocampus. We have analyzed NMDAR subunits levels in Wistar rats after 5 minutesexploration of an unique OF, in central structures other than the hippocampus, at differentages (30, 60 and 90 days old). There was an increase in GluN1 and GluN2A levels in thehippocampus about 1 hour after the OF session, though neither in the cerebral cortex norin the amygdala; that increase was reversible since the levels were not significantlydifferent from controls 24 h later, in all the ages assessed. We analyzed two other groupsof rats (30 and 90 days old) that were exposed to a second OF session (test). The 2nd OFsession was performed either 24 h or up to 2 month after the 1st session. GluN1 andGluN2A levels increased in the prefrontal cortex 60 minutes after the test, either 24 hs or 2months later. Our results suggest that the transient increase and rebalance of specificNMDAR subunits in structures involved in memory processing could be related to thememory tracing.