Dopamine D1/D5 Receptors in the Retrosplenial Cortex Are Necessary to Consolidate Object Recognition Memory

Abstract

The retrosplenial cortex (RSC) has been widely related to spatial and contextual memory. However, we recently demonstrated that the anterior part of the RSC (aRSC) is required for object recognition (OR) memory consolidation. In this study, we aimed to analyze the requirement of dopaminergic inputs into the aRSC for OR memory consolidation in male rats. We observed amnesia at 24-h long-term memory when we infused SCH23390, a D1/D5 dopamine receptors antagonist, into aRSC immediately after OR training session. However, the same infusion had no effect on OR short-term memory. Then, we analyzed whether the ventral tegmental area (VTA) is necessary for OR consolidation. VTA inactivation by intra-VTA administration of muscimol, a GABAA agonist, immediately after an OR training session induced amnesia when animals were tested at 24 h. Moreover, we observed that this VTA inactivation-induced amnesia was reversed by the simultaneous intra-aRSC delivery of SKF38393, a D1/D5 receptor agonist. Altogether, our results suggest that VTA dopaminergic inputs to aRSC play an important modulatory role in OR memory consolidation.

The Granular Retrosplenial Cortex Is Necessary in Male Rats for Object-Location Associative Learning and Memory, But Not Spatial Working Memory or Visual Discrimination and Reversal, in the Touchscreen Operant Chamber

“…Future studies should also explore the mechanistic roles played by the RSC in associative learning and memory. For instance, as glutamate, acetylcholine, and dopamine neurotransmitter systems have previously been implicated in PAL ( Day et al, 2003 ; Talpos et al, 2009 ; Bethus et al, 2010 ; Bartko et al, 2011 ; Harel et al, 2013 ; Lins and Howland, 2016 ), and there is evidence of each of these systems within the RSC ( Corcoran et al, 2011 ; Todd et al, 2019 ; Vallianatou et al, 2019 ; de Landeta et al, 2022 ), it would be advantageous in future studies to explore the neurotransmitters involved in the role of the RSC in associative learning.…”

Dual role of α7 nicotinic acetylcholine receptors in the retrosplenial cortex for aversive memory acquisition and retrieval

“…After completing the behavioral procedures, the positioning of the cannula was confirmed by the aRSC infusion of 1 µl of 4% methylene blue in saline. The extension of the dye was taken as indicative of the diffusion of the drug, as previously published (de Landeta et al, 2022). Only animals with both cannulae in the correct place were included in the analysis.…”