Effects of body temperature elevation on auditory nerve-brain-stem evoked responses and EEGs in rats.

ABRs and EEGs were recorded in anaesthetized rats during whole body hyperthermia. ABR amplitudes were decreased during warming, with little recovery as body temperature was lowered. The latencies of the ABR waves decreased with warming and increased with subsequent cooling. The major latency changes were in the later ABR waves. Warming was accompanied by suppression of the EEG. These results point out that ABR evaluation of patients must take into account elevated body temperatures. Since it has been shown that the rat can serve as a model of the effects of heat on man, an attempt is made to relate these ABR and EEG findings in rats to studies of human psychomotor performance during heat exposure.