RESUMO
Objective To study the effects of diabetes on hippocampal synaptic plasticity in perforant path-dentate gyrus pathway (PP-DG) in rats. Methods 70 SD rats( 180±20) g were divided into 3 groups at random: control group, type1 diabetes group (DM1)and type2 diabetes group (DM2). After Morris water maze test, 15 rats that showed worse spatial memory ability were selected in each model group to investigate the variation of paired-pulse facilitation (PPF) and the range of synaptic plasticity. Field potentials were recorded in the dentate gyrus of the dorsal hippocampus by stimulating the perforant path. Results Contrast to the control group, diabetic rats' hippocampal LTP were depressed (P<0.05), and type1 diabetic rats' LTP reduced much more. Diabetic rats' PPF ratio was reduced contrast to the control group (P<0.05). Conclusion Type1 and type2 diabetes impaired synaptic plasticity of hippocampal PP-DG pathway in rats, which conformed the results of water maze test.