Abstract: Objective To observe the effects of autophagy on the expression of synaptic plasticity related protein, growth-associated protein- 43 (GAP-43) and microtubule associated protein-2 (MAP-2), in CA1 area of hippocampus of vascular dementia rats. Methods Ninety- six healthy male Sprague-Dawley rats were randomly divided into sham group, vascular dementia model group (VD group), autophagy inhibitor 3-methyl adenine preconditioning group (3-MA group) and autophagy agonist rapamycin preconditioning group (Rap group). Each group was divided randomly into subgroups of one week, two weeks, four weeks and eight weeks after modeling, six rats in each group. The vascular dementia rat model was established with modified Pulsineli's four-vessel occlusion. The expression of GAP-43 and MAP-2 in CA1 area of hippocampus were detected with immunohistochemistry. Results Compared with the sham group, the expression of GAP-43 protein increased, and the expression of MAP-2 protein decreased at every time point in VD group (P<0.01). Compared with VD group, the expression of both GAP-43 and MAP-2 increased in 3-MA group (P<0.05), and decreased in Rap group (P<0.05). Conclusion Autophagy may inhibit the expression of synaptic plasticity related protein, GAP-43 and MAP-2, in CA1 area of hippocampus in vascular dementia rats, indicating inhibition of autophagy may promote synaptic remodeling.

Key words: vascular dementia, autophagy, growth-associated protein-43, microtubule associated protein-2, synaptic plasticity, rats