Extinction learning efficiency in Neohelice granulata depends on the proximity to the original memory acquisition. An explanation correlated to the NMDA receptor surface expression dynamics.

ABAHI ROSSO; RAMIRO FREUDENTHAL

Congreso; REUNIÓN ANUAL SAN 2019; 2019

SAN

Context-signal memory (CSM) can be induced in the crab Neohelice granulata through spaced training, and it?s dependent on NMDA-like receptor activity. It was found in that the surfaceexpression of the GluN1 subunit of the NMDA type receptors in the central brain is altered during consolidation. While the total amount of the receptor remains constant, surface expression ofGluN1 is down-regulated immediately after training, up-regulated 3 hr after training, and returns to naïve and control levels 24 hr after training. These changes seem to be related with thecapacity of adding information to a mnesic trace: a decrease in GluN1 surface expression wouldn?t allow further activation through the receptor, affecting the incorporation of new informationto the previous memory. On the contrary, the increment in GluN1, once the consolidation process is advanced, could reflect a higher probability of activation, facilitating the addition of newinformation.To test this hypothesis we focused on the extinction learning (dependent on NMDA receptor activity for acquisition) that occurs when exposing the animals to the training context, thusenabling a second learning event at the post-training points when surface expression is altered.