||Differential Impact of Hypothermia and Pentobarbital on Brain-Stem Auditory Evoked Responses.
Janssen, R. ;
Hetzler, B. E. ;
Creason, J. P. ;
Dyer, R. S. ;
||Health Effects Research Lab., Research Triangle Park, NC. ;Lawrence Univ., Appleton, WI.
Auditory brain stem evoked potentials ;
Body temperature regulation ;
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||Two experiments were conducted to determine the effects of hypothermia and pentobarbital anesthesia, alone and in combination, on the brain-stem auditory evoked responses (BAERs) of rats. In experiment I, unanesthetized rats were cooled to colonic temperatures 0.5 and 1.0 C below normal. In experiment II, 2 groups of rats were cooled and tested at 37.5, 36.0, 34.5 and 31.5 C. One group was anesthetized during testing and the other group was awake. The rat BAER was sensitive to cooling of 1 C or less. Peak latencies were prolonged and peak-to-peak amplitudes were increased by hypothermia alone. The effect on amplitude may be related to the time course of temperature change or to stimulus level. Pentobarbital significantly affected both latencies and amplitudes over and above the effects of cooling. The specific effects of pentobarbital differed by BAER peak and by temperature. The findings point up the importance of the potential confound of anesthetic drugs in most of the evoked potential literature on hypothermia and, for the first time, quantify the complex interactions between pentobarbital and temperature which affect the BAER wave form. (Copyright (c) 1991 Elsevier Scientific Publishers Ireland, Ltd.)
||Pub. in Electroencephalography and Clinical Neurophysiology, v80 n5 p412-421 Sep 91. Prepared in cooperation with Lawrence Univ., Appleton, WI.
|NTIS Title Notes
||Reprint: Differential Impact of Hypothermia and Pentobarbital on Brain-Stem Auditory Evoked Responses.
||57Q; 57W; 57I
||PC A03/MF A01