A QUANTITATIVE INVESTIGATION ON SYNAPTIC STRUCTURAL PLASTICITY IN THE BRAIN OF MICE TREATED WITH DGAVP
Luo Lan, Lu Hanxin, Wu Fumei, Xiao Xinsheng(Department of Biology, Nanjing University, Nanjing)
The changes of some parameters of Gray type Ⅰ synaptic interface in the brain of mice treated with desglycinamide-arginine-8-vasopressin (DGAVP) have been analysed quantitatively two hours after DGAVP injection. The animals were killed and the hippocampus and sensori-motor area of cerebral cortex were prepared for electron microscopy. The electron microphotographs were analysed by IBM-PC computer image processing system. The main results of the experiment are as follows: 1. The thickness of postsynaptic density apparently increased in both the sensori-motor area of cerebral cortex and CA_3 area of hippocampus after injection of DGAVP (P0.01). 2. There was a significant decrease in the degree of curvature of synaptic interface (P0.01) and the width of synaptic cleft (P0.05) in hippocampus of DGAVP group, while no changes was found in sensori-motor area. 3. The length of synaptic active zone showed no significant change between the DGAVP group and the control group in both sensori-motor area of cerebral cortex and CA3 area of hippocampus. Our results suggest that the central effects of DGAVP may be related with the structural plasticity of excitatory synapse in mice brains.