CONICET | Buscador de Institutos y Recursos Humanos

P { margin-bottom: 0.21cm; }NMDA receptors (NMDAR) play acritical role in synaptic plasticity, are required for memoryencoding and ?storage?, participate in plasticity during centralnervous system (CNS) development, like synaptogenesis and synapsematuration, and also in neurodegenerative disorders like Alzheimerand Parkinson disease (Paoletti et al., 2013). NMDAR areheterotetramers composed by 2 GluN1 obligatory subunits and 2regulatory subunits, being GluN2A and GluN2B the major regulatorysubunits in CNS regions involved in cognitive functions. We havepreviously shown that about 1 hour after memory acquisition of ahippocampus depending task (open field [OF] habituation) or after theeffective induction of LTP in fresh hippocampal slices, GluN1 andGluN2A expression transiently increased in the hippocampus (BaezMV et al., 2013). In this workwe analyze NMDAR subunits levels in Wistar rats after 5 minutesexploration of an unique OF, in central structures other than thehippocampus, at different ages (30, 60 and 90 days old). There was anincrease in GluN1 and GluN2A levels in the hippocampus about 1 hourafter the OF session, though not in the cerebral cortex or theamygdala; that increase was reversible since the levels were notsignificant different from controls 24 h later in all ages assessed.We then analyzed two other groups of rats (30 and 90 days old) thatwere exposed to a second OF session (test). Both groups, rats testedin a 2nd OF session 24 h or up to 2 month after the 1st session,showed habituation to the OF. GluN1 and GluN2A levels increased onlyin the prefrontal cortex 60 minutes after the test, either 24 hs or 2months later. Our results suggest that the transient increase andrebalance of specific NMDAR subunits in structures involved in memoryprocessing could be part of the memory tracing.