Changes in NMDAR subunits levelsafter an object recognition task

CERCATO, MAGALÍ; JERUSALINSKY, DIANA; KORNISIUK, EDGAR; COLETTIS, NATALIA; BAEZ, MARÍA V.

Buenos Aires

Congreso; 2do Congreso de Federation of Latin American and Caribbean Neuroscience Societies; 2016

Federation of Latin American and Caribbean Neuroscience Societies

P { margin-bottom: 0.21cm; direction: ltr; widows: 2; orphans: 2; }NMDAreceptors (NMDAR) play a critical role in synaptic plasticity, memoryencoding and storage, are heterotetramers composed by two obligatoryGluN1 and two regulatory subunits: GluN2 (A-D) or GluN3 (A-B), beingGluN2A and GluN2B the major regulatory subunits in cognitivefunctions related areas. We have already shown that there was anincrease of GluN1 and GluN2A 70? afterhabituation to a newenvironment in the hippocampus of1, 2 and 3 month old Wistar rats. Aswe hypothesize thatNMDAR subunits increase could be related to memorytracing, we decided to investigate if those changes could take placefollowing other learning tasks like an objectrecognitiontask (OR). In the training session (Tr) rats were exposed to twoidentical novel objects (A-A?) for 5? in a familiar arena; therewas no significant difference in the exploration time spent at eachobject. In the test session (Te) each rat was reintroduced into thearena for 5? with either a familiar and a novel object (A-B) or twofamiliar objects (A-A?); they spent significantly longer exploringthe novel object than the familiar one. After Tr or Te rats wereeuthanized and hippocampal extracts were analyzed by westernblot.There was a significant increase in hippocampal GluN1 and GluN2Alevels only 70? post-Tr though not after Te, nor at the hippocampusneither at CPF. These results suggest that changes in NMDAR subunitsof the hippocampus could be part of the trace of new acquiredmemories.