Jamieson M G, Fink G
J Endocrinol. 1976 Jan;68(1):57-70. doi: 10.1677/joe.0.0680057.
The release of LH and FSH after the application of an electrical stimulus to the anterior diencephalon of male rats has been studied. The stimulus was applied through either platinum or steel electrodes implanted stereotaxically in animals anaesthetized with urethane. The efficacy of various parameters of stimulation by means of a current consisting of balanced biphasic square waves, was tested by systematically changing the frequency, amplitude and duration of the pulses. The effect of direct current (d.c.) stimulation on hormone release was also examined. The concentrations of the hormones in blood withdrawn from the femoral vein before and at frequent intervals up to 80 min after application of the stimulus were determined by radioimmunoassay. The optimal parameters for the release of LH by square wave stimulation of the medial preoptic area were: frequency, 60 Hz; pulse amplitude, 0-50 mA; pulse duration, 1-00 ms. This stimulus was more effective when applied through steel than through platinum electrodes. Direct current stimulation (15 muA for 10 s) through steel electrodes was most effective of all. When applied through platinum electrodes to the medial preoptic and anterior hypothalamic areas, the optimal square wave stimulus produced significant increases in the concentration of LH after 5 and 10 min respectively. The concentration of plasma FSH in these animals also increased, but the increments were much less than the increments in LH. The magnitude of the respective increases of the gonadotrophins after stimulation of the two brain areas did not differ significantly. Measurement of the milk ejection response to stimulation of the hypothalamo-hypophysial tract in the lactating rat indicated that the spread of the square wave stimulus was no more than 1-5 mm from the electrode tip. The significance of these findings is discussed with respect to the importance of the medial preoptic area in the male rat, the neurones which may be involved in the regulation of gonadotrophin secretion, and the parameters of stimulation used in studying the hypothalamo-hypophysial system.
研究了对雄性大鼠间脑前部施加电刺激后促黄体生成素（LH）和促卵泡生成素（FSH）的释放情况。刺激通过立体定位植入用乌拉坦麻醉的动物体内的铂电极或钢电极施加。通过系统改变由平衡双相方波组成的电流的频率、幅度和持续时间，测试了各种刺激参数的效果。还研究了直流电（d.c.）刺激对激素释放的影响。通过放射免疫分析法测定了在施加刺激前以及直至刺激后80分钟的频繁间隔时间从股静脉抽取的血液中激素的浓度。通过方波刺激内侧视前区释放LH的最佳参数为：频率60赫兹；脉冲幅度0 - 50毫安；脉冲持续时间1.00毫秒。这种刺激通过钢电极施加比通过铂电极更有效。通过钢电极进行的直流电刺激（15微安，持续10秒）最为有效。当通过铂电极施加于内侧视前区和下丘脑前部区域时，最佳方波刺激分别在5分钟和10分钟后使LH浓度显著升高。这些动物血浆FSH的浓度也有所升高，但升高幅度远小于LH的升高幅度。刺激两个脑区后促性腺激素各自升高的幅度无显著差异。对泌乳大鼠下丘脑 - 垂体束刺激的排乳反应测量表明，方波刺激从电极尖端的扩散不超过1.5毫米。结合内侧视前区在雄性大鼠中的重要性、可能参与促性腺激素分泌调节的神经元以及研究下丘脑 - 垂体系统时使用的刺激参数，对这些发现的意义进行了讨论。
