A Study On Cognitive Deficits And Changes Of Cerebral Choline Acetyltransferase Following Multiple Cerebral Concussion

Objective: To establish the model of multiple cerebral concussion(MCC) in rats as well as the change of cerebral choline acetyltransferase following multiple cerebral concussion in basal ganglia, prefrontal lobe and septal area, Our aim is to study the relationship between cognitive deficits and the changes of cerebral choline acetyltransferase after MCC in rats, thus to provide some preventive and treatment theories for sports-related cerebral concussion (SRCC) .Methods: Animal model were duplicated by using a metallic pendulum striker concussive device. The injured rats were randomly divided into 1d, 2d, 4d, 8d, 16d and 24d group after MCC.Each group is 8 animals (n =8). Additionally,8 intact rats as one control group. Brain Choline acetyltransferase (ChAT) content in the prefrontal cortex,the basal ganglia and medial septal area was measured by Western blotting technique with ChAT specific antibody. Morris water Maze were measured on days 1-15 after injury to evaluate Spatialearning and memory ability.Results: (1) The results of Morris Water Maze: From the first day to the 15th day after MCC, the latency to find the hidden platform was much longer and there were significant differences on the 4th, 6th, 8th, 10th～15th day compared with the control group.Spatial probe test demonstrated that the MCC produced obvious reduction of dwell time in the target quadrant, while the prominent increase of dwell time in the second quadrant (P < 0.05 vs.control) . (2)The results of Western Blotting :Compared with the control group, the expression of ChAT in each brain area decreased post concussion. There were significant differences in the prefrontal cortex from 2th to 16th day after injury, in the basal ganglia from 2nd to 24th day, and medial septal area from 1st to 16th day post injury.Conclusions: ( 1 ) The multiple cerebral concussion ( MCC ) model in rats was established successfully using a metallic pendulum-striker concussive device; (2) MCC created severe learning and memory dysfunction and late deficits in rats; (3) The change of cholinergic system correlate with cognitive deficits in MCC rats.