刺激下丘脑弓状核或垂体前叶对丘脑束旁核神经元伤害性反应的抑制

采用电生理学方法，观察电刺激大鼠下丘脑弓状核（ＡＲＣ）或垂体前叶（ＡＬ），对丘脑束旁核（Ｐｆ）神经元伤害性反应的影响。实验结果表明，电刺激ＡＲＣ能抑制Ｐｆ神经元的伤害性放电，这种抑制很快出现，也很快恢复，称为即时抑制。电刺激Ａ辄能抑制Ｐｆ神经元的伤害性放电，这种抑制的出现有一定的潜伏期，并持续较长时间，称为延迟抑制。摘除垂体减弱刺激ＡＲＣ的即时抑制，而损毁ＡＲＣ则减弱刺激ＡＬ的延迟抑制。地塞米松预

INHIBITORY EFFECTS OF HYPOTHALAMIC ARCUATE NUCLEUS OR ANTERIOR PITUITARY STIMULATION ON THE NOCICEPTIVE RESPONSES OF THALAMIC PARAFASCICULAR NEURONS

The effects of hypothalamic arcuate nucleus (ARC) or anterior lobe of pituitary (AL) stimulation on the nociceptive responses of thalamic parafascicular (Pf) neurons were studied in rats with electrophysiological technique. The results showed that ARC stimulation could inhibit the nociceptive discharges of Pf neurons, namely, the immediate inhibition because of its very short latency and duration. AL stimulation could also inhibit the nociceptive discharges of Pf neurons, but this inhibition was a delayed one because of its longer latency and duration. Hypophysectomy diminished the immediate inhibition due to ARC stimulation, while ARC lesion diminished the delayed inhibition due to AL stimulation. Both kinds of inhibition were blocked by dexamethasone pretreatment. The above results suggest that neuroendocrine relationship between ARC and AL is involved in pain modulation.