Dopamine in the retrosplenial cortex controls the consolidation of object recognition long-term memory.

DE LANDETA, AB; MEDINA, JORGE H.; KATCHE C

Congreso; 3rd Congress of the Federation of Latin American and Caribbean Neuroscience Societies (FALAN); 2022

We have recently demonstrated that the RSC (RSC) is required for object recognition (OR) memory consolidation. As dopamine has been previously related to OR memory formation in other brain regions; here, we aimed to analyze the requirement of dopaminergic inputs into the RSC for OR memory consolidation in Wistar male rats. We first studied the dopaminergic requirement for memory consolidation. We infused SCH23390, a D1/D5 dopamine receptors antagonist (0.75 µg/side, in saline), into the RSC immediately after OR training session. We bserved 24 h long-term memory amnesia provoked by SCH23390. However, SCH23390 infusion immediately after OR training session did not affect 3 h short-term memory. Afterwards, we evaluated the requirement of ventral tegmental area (VTA) activity for OR memory consolidation. We inactivated VTA by muscimol, a GABA A agonist (0.1 µg/side, in saline), infusion immediately after OR training session. We observed 24 h amnesia when inactivating VTA. Additionally, this amnesia could be prevented when infusing at the same time SKF38393, a D1/D5 agonist (12.5 µg/side, in 10% DMSO), into the RSC. Taken together, our results showed that dopamine plays a major role in OR memory consolidation, demonstrating that this neurotransmitter is necessary and sufficient for OR memory consolidation in the RSC. Moreover, our results suggest that dopamine might be release from VTA to RSC, in order to modulate OR memory.