Effect of ibotenic acid and colchicine infusion into the rat hippocampus in passive avoidance learninig

Current models of memory impairment involve the specific brain regions lesion, such as hippocampus, amygdale, nucleus basalis of magnucellularis (NBM) and entorinal cortex. There is some disagreement with respect to the specific roles of these structures, perhaps due to sub regional differences within each area. The aim of the present study was to evaluate the effect of intra-hippocampal administration of ibotonic acid and cholchicine on associative aversive memory.

Forty male Wistar rats were used in this study. Animals were cannulated bilaterally in the CA1 and dentate gyrus of the hippocampus for infusion of ibotonic acid and cholchicine(8 g/ l) respectively. Then step down passive avoidance learning (PAL) was used 14 days later. Data was analyzed by independent T-test, and p<0.05 considered as statistically significant.

Intra dentate gyrus administration of 8 g/ l colchicine did not show PAL (p > 0.05). Also intra CA1 administration of ibotenic acid didn’t demonstrate significant change in memory retention tested 24 h after training compared to related vehicle control groups (p >0.05).

Our findings showed that single dose of colchicine or ibotenic acid targeting CA1 and dentate gyrus of hippocampus has no significant change on associative memory in passive avoidance learning paradigm.