Down-regulation of the hippocampal connexin43 during inhibitory avoidance memory consolidation

Background and Aim : Studies have shown that the intercellular communication via gap junction channels has a crucial role in the learning process. Amongst different types of connexins, connexin 43 (Cx43) is the most widely expressed and studied gap junction proteins in astrocytes. Both memory formation and memory deteriorating functions of astrocytes-located connexins have been documented. In this study, we measured the expression levels of Cx43 in the hippocampus of rats, during inhibitory avoidance memory consolidation.Methods : Adult male Wistar rats weighing 250 g were used. Animals were trained with the inhibitory avoidance task. At different times post-training (1, 3 and 24 h), the rats were decapitated and their hippocampus was removed and freeze in liquid nitrogen, immediately. The control group did not receive any electric shock. The mRNA expression level of Cx43 was measured by the real-time PCR method.Results : One-way ANOVA indicated a significant decrease in the expression levels of the hippocampal Cx43 during inhibitory avoidance memory consolidation. Post-hoc comparison showed that the expression levels of Cx43 decreased at 1 h post-training compared to the control group.Conclusion : The results indicate that the intercellular communication between hippocampal astrocytes decrease via Cx43 made gap junctions during fear memory consolidation. The decreased expression of Cx43 might have a role in the inhibitory avoidance memory consolidation, which needs to be clarified.

کلیدواژه ها:

Astrocyte ، Connexin43 ، Hippocampus ، Inhibitory avoidance memory