Cognition, Behavior, and Memory
Author: Juliana Fátima Dalto | email: julianadalto@hotmail.com
Juliana Fátima Dalto 1°, Jorge Horacio Medina 1°
1° Instituto de Biología Celular y Neurociencias Prof. Eduardo de Robertis, Facultad de Medicina, UBA-CONICET
Understanding the mechanisms by which memory is naturally forgotten is as important as understanding how it is stored. Recently, we demonstrated that dopamine neurotransmission in the hippocampus (HP) and the ventral tegmental area (VTA) of the rat is involved in the active forgetting (AF) of consolidated appetitive memories. Now, we aim to unravel the processes underlying the forgetting of consolidated aversive memories (CAMs). So far, we found no evidence for a role of dopamine or GABA neurotransmission in the AF of CAMs. Other studies proposed that the GTPase Rac1 has an active role in the forgetting of different types of memories. However, the participation of this protein in the AF of CAMs is not well understood. Here, we assessed the role of Rac1 in the AF of inhibitory avoidance (IA) memory at different regions of the brain and different moments after acquisition. In the HP, the inhibition of Rac1 after training or after retrieval did not affect IA memory. However, post-training but not post-retrieval inhibition of Rac1 in the VTA potentiated IA memory at 24 h and 14 d after training. This effect was not due to facilitation of memory formation since memory at 1 h after training was not altered even with a weaker training. Moreover, the inhibition of Rac1 in the VTA at 12 h after training reduced the expression of the IA memory at 24 h suggesting the possibility that this protein could have different effects on memory depending on the moment after acquisition.