Changes in pre and post synaptic proteins during LTM early consolidation

GOBBINI, MARIA LAURA; BAEZ, MARÍA VERÓNICA; CANAL, MARIA PILAR; ACUTAIN, MARIA FLORENCIA

Congreso; XXXIV Reunión Anual SAN 2019; 2019

Sociedad Argentina de Neurociencia (SAN)

Memory consolidation requires protein synthesis and degradation. In this way, it was described that postsynaptic receptors change its expression after memory acquisition or plasticity induction:NMDAR expression rise 70 minutes and decrease, to control levels, 90 minutes after training, while AMPAR expression is increased long after 90 minutes. On the other hand, NMDAR and AMPAR are associated to scaffold proteins that help to assemble the postsynaptic density (PSD) and are called MAGUKs (membrane-associated guanylate kinases). These MAGUKs are: PSD93, PSD95, PSD97 and SAP102. GluN2A, a NMDAR regulatory subunit is directly associated to PSD95. Furthermore, this last controls AMPAR number at PSD. In this work, we investigate changes in pre and postsynaptic sides, using a presynaptic (Synapsin1, Syn) and a postsynaptic marker (PSD95) 70 minutes after memory acquisition, at same time that NMDAR subunits rise.For this reason, we trained adult Wistar rat in an Inhibitory Avoidance paradigm (IA) and, immediately or 70 minutes after training, we dissected both hippocampi and analyze PSD95 and Syn1 expression by western blot, in total homogenates and also, in PSDs fractions. We found that Syn1 levels were increased in membrane fractions while PSD95 did not change it expression in both total and PSDs homogenates. These results could suggest that changes in pre and postsynaptic sides have different dynamics that we will investigate in a near future.