Experimental head injury in the rat. Part 1: Mechanics, pathophysiology, and morphology in an impact acceleration trauma model.

Impact acceleration was used to elicit cerebral concussion in the albino rat. The pathophysiological response and morphological damage from the concussion were studied in groups of animals. The animals were grouped according to impact velocity (6-11 m/sec), and the threshold and different degrees of the concussive response were established. The concept of concussion as primarily a neuronal, functional disturbance was confirmed. However, this reaction was readily influenced by respiratory and circulatory changes, and morphological damage. Defined reactions could be elicited in groups of animals according to impact velocity. Thus, the model appeared well standardized for further studies of concussion pathophysiology, expressed in terms of cerebral energy metabolism and blood flow.