Effects of hyper +Gz acceleration on brainstem and auditory cortical evoked potentials and cerebral blood flow in anesthetized rats.

Hypergravity acceleration along the long axis of the body (Gz) causes severe cardiovascular dysfunctions. Many studies have been conducted along this line. However, most previous studies used rather a short duration of hyper-Gz application, up to 30 sec, because application of large hyper-Gz brings animals into death. In order to elucidate effects of long duration of Gz application, we made experiments with Gz load for as long as 1000 sec. Cardiovascular dysfunctions and reduction of arterial blood pressure were usually accompanied by reduction of cerebral blood flow, leading subjects into loss of consciousness and into death. Recently, we studied the effects of +Gz load on evoked potentials. The present experiments shows effects of +Gz on brainstem auditory response and auditory evoked potentials.