Mechanisms Of Melatonin In Improving Lead-induced Rat Learning And Memory Impairments

Objective: To investigate the mechanisms of melatonin improving lead-induced rat learning and memory impairments by regulating neurogenesis,astrocytes and cholinergic neurons of basal forebrain. Methods: Healthy adult Wistar rats were randomly divided into three groups: normal control group, with 10 per group, lead acetate-treated group(30 mg/kg,i.p),and lead acetate plus melatonin(20 ug/kg,i.p). Immunohistochemical analyses were made on bromodeoxyuriding (BrdU), ChAT, GFAP and NF positive cells, Double-immunohistochemical analyses made on BrdU+GFAP , BrdU+NF positive cells, The abilities of learning and spatial memory were tested in Morris water maze. Results: The number of BrdU-positive cells in the subventricular zone(SVZ) and in the subgranular zone (SGZ) of dentate gyrus,and the numbers of ChAT-positive cells in medial septum (MS)and diagonal band of the basal forebrain were significantly decreased in lead exposed group (P<0.01).