Donevan S D, Ferguson A V
Department of Physiology, Queen's University, Kingston, Ont., Canada.
Neuroendocrinology. 1988 Jul;48(1):67-71. doi: 10.1159/000124991.
We have examined the effect of electrical stimulation in the subfornical organ (SFO) on the activity of neurons in the medial septum and diagonal band of Broca (MS-DBB) which project to the median eminence in the rat. Previous studies have suggested that septal neurons with such projections are luteinizing hormone releasing hormone neurons. Extracellular single-unit recordings were obtained from 69 neurons in the MS-DBB which were antidromically identified as projecting to the median eminence. Electrical stimulation (100-400 microA) in the SFO resulted in a relatively short-latency (22.8 +/- 0.8 ms), short-duration (9.2 +/- 0.8 ms) activation of 85% of 41 antidromically identified MS-DBB neurons tested. One neuron was inhibited by SFO stimulation, while the remaining 12% were unaffected. Stimulation in nearby regions, including the hippocampal commissure and paraventricular nucleus of the thalamus, failed to elicit a similar excitatory response from 19 identified MS-DBB neurons. These results identify a neuronal pathway between the SFO and septal neurons which project to the median eminence, supporting a possible role for the SFO in the control of luteinizing hormone releasing hormone release and hence gonadotropin secretion.
我们研究了穹窿下器（SFO）的电刺激对大鼠中隔内侧核和布罗卡斜角带（MS-DBB）中投射至正中隆起的神经元活动的影响。先前的研究表明，具有这种投射的隔区神经元是促黄体生成素释放激素神经元。从69个MS-DBB神经元中获得了细胞外单单位记录，这些神经元经逆向鉴定为投射至正中隆起。SFO中的电刺激（100 - 400微安）导致41个经逆向鉴定的受试MS-DBB神经元中有85%出现相对短潜伏期（22.8±0.8毫秒）、短持续时间（9.2±0.8毫秒）的激活。一个神经元受到SFO刺激的抑制，其余12%未受影响。对包括海马连合和丘脑室旁核在内的附近区域进行刺激，未能在19个已鉴定的MS-DBB神经元中引发类似的兴奋反应。这些结果确定了SFO与投射至正中隆起的隔区神经元之间的神经通路，支持了SFO在控制促黄体生成素释放激素释放以及由此控制促性腺激素分泌方面可能发挥的作用。
