Stanton T L, Caine S B, Winokur A
Department of Physiology, California State University, Long Beach 90840.
Brain Res Bull. 1992 Jun;28(6):877-86. doi: 10.1016/0361-9230(92)90208-f.
Quantitative autoradiography was used to localize and quantify thyrotropin-releasing hormone (TRH) receptors in the brain of hibernating (H), winter euthermic (WE), and summer euthermic (SE) animals to further explore the state-dependent physiological and behavioral effects of TRH in ground squirrels. The pattern of [3H]MeTRH binding (Kd 6.7 +/- 0.1 nM) was heterogeneous and highly concentrated in structures primarily associated with the limbic forebrain. Statistically significant seasonal changes (SE vs. WE) were reflected by decreases in TRH receptor binding in the arcuate nucleus, dorsomedial nucleus, and ventral pallidum of WE animals. Increased binding in WE animals was evident in the suprachiasmatic nucleus and choroid plexus of the lateral ventricles. Significant state-dependent changes (WE vs. H) were characterized by decreases in TRH receptor binding in the hypothalamic paraventricular nucleus, medial preoptic area, ventral tegmental area, and choroid plexus of the lateral ventricles of H animals. Increased binding occurred in the anterior cortical nucleus of the amygdala in H animals. The results suggest that naturally occurring changes in central TRH systems may be important in the mediation of physiological and behavioral processes that undergo seasonal and state-dependent adjustments in hibernating mammals.
采用定量放射自显影术对冬眠（H）、冬季常温（WE）和夏季常温（SE）动物大脑中的促甲状腺激素释放激素（TRH）受体进行定位和定量，以进一步探究TRH对松鼠生理和行为的状态依赖性影响。[3H]MeTRH结合模式（解离常数Kd为6.7±0.1 nM）呈异质性，且高度集中于主要与边缘前脑相关的结构中。WE动物的弓状核、背内侧核和腹侧苍白球中TRH受体结合减少，反映出显著的季节性变化（SE与WE相比）。WE动物视交叉上核和侧脑室脉络丛中的结合增加。显著的状态依赖性变化（WE与H相比）表现为H动物下丘脑室旁核、内侧视前区、腹侧被盖区和侧脑室脉络丛中TRH受体结合减少。H动物杏仁体前皮质核中的结合增加。结果表明，中枢TRH系统的自然变化可能在介导冬眠哺乳动物中经历季节性和状态依赖性调节的生理和行为过程中起重要作用。
