Changes in NMDAR subunits levels after an object recognition task

COLETTIS, NATALIA; BAEZ, M. VERÓNICA; KORNISIUK, EDGAR; CERCATO, MAGALI; JERUSALINSKY, DIANA ALICIA

Ciudad autonoma de Buenos Aires

Congreso; 2nd FALAN Congress; 2016

Federation of Latin American and Caribbean Neuroscience Societies/ Sociedad Argentina de Investigación en Neurociencias

NMDA receptors (NMDAR) playa critical role in synaptic plasticity, memory encoding and storage, areheterotetramers composed by two obligatory GluN1 and two regulatory subunits:GluN2 (A-D) or GluN3 (A-B), being GluN2A and GluN2B the major regulatorysubunits in cognitive functions related areas. We have already shown that therewas an increase of GluN1 and GluN2A 70? after habituation to a new environmentin the hippocampus of 1, 2 and 3 month old Wistar rats. As we hypothesize that NMDARsubunits increase could be related to memory tracing, we decided to investigateif those changes could take place following other learning tasks like an objectrecognition task (OR). In the training session (Tr) rats were exposed to two identical novel objects (A-A?) for 5? in a familiararena; there was no significant difference in the exploration time spent ateach object. In the test session(Te) each rat was reintroduced into the arena for 5? with either a familiar and a novel object (A-B) or two familiarobjects (A-A?); they spent significantly longer exploring the novel object thanthe familiar one. After Tr or Te rats were euthanized and hippocampal extractswere analyzed by westernblot. There was a significant increase in hippocampal GluN1and GluN2A levels only 70? post-Tr though not after Te, nor at the hippocampusneither at CPF. These results suggest that changes in NMDAR subunits of thehippocampus could be part of the trace of new acquired memories.