Barrett J A, Edinger H, Siegel A
Department of Physiology, New Jersey Medical School, University of Medicine and Dentistry of New Jersey, Newark.
Brain Res. 1990 Aug 20;525(2):285-93. doi: 10.1016/0006-8993(90)90876-d.
The purpose of this study was to investigate the effects of noradrenergic agents infused into the anterior hypothalamus on feline affective defense responses elicited by electrical stimulation of the ventromedial hypothalamus. Anterior hypothalamic sites which are known to receive inputs from both the ventromedial hypothalamus and ascending noradrenergic pathways were selected for pharmacological analysis. Intracerebral infusions of NE (1.2-2.4 nmol) into the anterior hypothalamus significantly reduced the threshold current required to elicit the hissing component of affective defense via electrical stimulation of the ventromedial hypothalamus. Maximal threshold reductions (17 +/- 3% to 20 +/- 3%) were observed 30 min following infusion. Anterior hypothalamic infusions of clonidine facilitated feline affective defense by reducing hissing current thresholds by 18 +/- 4%. Clonidine-induced changes in response thresholds parallel those obtained with NE. Both NE-induced and clonidine-induced reductions in current thresholds were reversible by pre- and post-treatment of the anterior hypothalamic sites with yohimbine. These results demonstrate that the reductions in response thresholds are mediated by post-synaptic alpha 2-adrenoceptors located within the anterior hypothalamus. Thus the noradrenergic system may play an important role in the regulation of affective aggressive behavior.
本研究的目的是调查向下丘脑前部注入去甲肾上腺素能药物对电刺激下丘脑腹内侧核引发的猫的情感防御反应的影响。选择已知接受来自下丘脑腹内侧核和去甲肾上腺素能上行通路输入的下丘脑前部位点进行药理学分析。向下丘脑前部脑室内注入NE（1.2 - 2.4 nmol）可显著降低通过电刺激下丘脑腹内侧核引发情感防御的嘶嘶声成分所需的阈电流。注入后30分钟观察到最大阈电流降低（17±3%至20±3%）。向下丘脑前部注入可乐定可使猫的情感防御反应增强，使嘶嘶声电流阈值降低18±4%。可乐定引起的反应阈值变化与NE引起的相似。NE和可乐定引起的电流阈值降低可通过用育亨宾对下丘脑前部位点进行预处理和后处理而逆转。这些结果表明，反应阈值的降低是由位于下丘脑前部的突触后α2 - 肾上腺素能受体介导的。因此，去甲肾上腺素能系统可能在情感攻击行为的调节中起重要作用。
