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ADAPTIVE CHANGES OF PREOPTIC THERMOSENSITIVE NEURONS IN HYPOTHALAMIC TISSUE SLICES OF RATS AFTER LONG-TERM EXPOSURE TO COLD ENVIRONMENTAL TEMPERATURE

SUN JIU-RONG, MA YONG-CHAO, ZHAO WEN-JIAN , CAI YI-PENG

Department of Physiology, College of Life Sciences, Peking University, Beijing 100871)

Abstract

In the present work，thermosensitivity and spontaneous firing rate of 86 preoptic neurons in hypothalamic tissue slices from 20 cold acclimated rats (CR，at 5士1℃for more than 3 weeks) and 127 neurons from 35 warm acclimated rats (WR，at 20士3℃for the same period) were recorded and compared. The results showed that:(1)The percentage of cold-sensitive neurons in CR were higher than that in WR，the critical temperature and the lowest temperature of the spontaneous firing activity of cold-sensitive neurons in CR were also lower than that in WR. (2) Thermosensitivity and critical temperature of the warm-sensitive neurons in CR were remarkably decreased，and spontaneous firing rate under 37℃ was increased. (3) Spontaneous firing rate (37℃)of
temperature insensitive neurons in CR were conspicuously increased and the lowest ternperature extended downward. These profound changes in response to long-term cold exposure suggested that plasticity of preoptic neurons was involved in the thermoregulation in cold adaptation.

Key words: hypothalamic slice;preoptic thermosensitive neurons; cold acclimation;cold tolerance; neuronal plasticity

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Citing This Article：

SUN JIU-RONG, MA YONG-CHAO, ZHAO WEN-JIAN , CAI YI-PENG. ADAPTIVE CHANGES OF PREOPTIC THERMOSENSITIVE NEURONS IN HYPOTHALAMIC TISSUE SLICES OF RATS AFTER LONG-TERM EXPOSURE TO COLD ENVIRONMENTAL TEMPERATURE . Acta Physiol Sin 1996; 48 (5): (in Chinese with English abstract).