Learning ability and spatial memory status in rats during the acute period of mild blast-induced traumatic brain injury

Abstract

The mild blast-induced brain traumatic injury like a battle fatigue, leads to neurological disability, including due to a violation of spatial memory. The presented work is the result of a blast-induced brain traumatic injury study on a self-developed device. For the experiment, 15 white Wistar rats were used and were divided into 3 groups: rats of Experimental group exposed by air shock wave (26–36 кPа); Sham group (anesthesia with halothane and fixation in a horizontal position) and Intact group. The ability to learning (food reinforcement) and the spatial memory state (time to search for food, vertical locomotor activity) were studied in the complex maze during the first 5 days of the posttraumatic period. To assess the emotional state, we counted the number and observed the quality of grooming acts. All researches were conducted in compliance with modern standards for humane attitude of animals. The results of our study clearly indicate a violation of spatial memory, which was manifested in the time of searching lengthening of the feeder and in the increase of vertical locomotor activity in the rats of the experimental group, while the animals clearly remembered that they were looking for food. The analysis of grooming showed qualitative changes in the form of incomplete and prolonged acts. Such changes indicate the development of anxiety in rats with mild blast-induced traumatic brain injury. This, in turn, led to deterioration of the spatial orientation and memory formation. Thus, the consequence of a mild blast-induced traumatic brain injury in the acute period is changes in the cognitive function of the brain in the form of deterioration of spatial memory, which was aggravated by a disturbance of emotionality in the form of anxiety. At the same time, the memory regarding the presence of food was formed adequately. Keywords: explosion, central nervous system, cognitive function, memory, maze.