De Boer P A, Ter Maat A, Pieneman A W, Croll R P, Kurokawa M, Jansen R F
Department of Organismal Neurobiology, Faculty of Biology, Vrije Universiteit, 1081 HV Amsterdam, The Netherlands.
J Neurophysiol. 1997 Dec;78(6):2823-33. doi: 10.1152/jn.1997.78.6.2823.
A morphologically defined group of peptidergic neurons in the CNS of the hermaphroditic snail, Lymnaea stagnalis, is concerned with the control of a very specific element of male sexual behavior. These neurons are located in the anterior lobe of the right cerebral ganglion (rAL). By using chronically implanted electrodes, we show that the rAL neurons are selectively active during eversion of the penis-carrying structure, the preputium. The preputium is normally contained inside the body cavity and is everted during copulation in the male role. Electrical stimulation of the rAL neurons through the implanted electrodes, induced eversion of the preputium in vivo. Injection of APGWamide (Ala-Pro-Gly-Try-NH2), a small neuropeptide that is present in all rAL neurons, induced eversion of the preputium. Application of APGWamide to in vitro preparations of the preputium caused relaxation of this organ. In contrast, injection of the neuropeptide conopressin, which is co-localized with APGWamide in 60% of the rAL neurons, did not induce any behavior associated with male sexual activities. These results show that the neurons of the rAL can induce an eversion of the preputium as occurs during male copulation by release of APGWamide during a period of electrical activity.
在雌雄同体的椎实螺（Lymnaea stagnalis）的中枢神经系统中，一组形态学上已明确的肽能神经元与雄性性行为中一个非常特定的行为要素的控制有关。这些神经元位于右侧脑神经节的前叶（rAL）。通过使用长期植入的电极，我们发现rAL神经元在携带阴茎的结构——阴茎包皮外翻期间有选择性地活跃。阴茎包皮通常包含在体腔内，在雄性交配时外翻。通过植入电极对rAL神经元进行电刺激，可在体内诱导阴茎包皮外翻。注射APGWamide（丙氨酸-脯氨酸-甘氨酸-色氨酸-酰胺），一种存在于所有rAL神经元中的小神经肽，可诱导阴茎包皮外翻。将APGWamide应用于阴茎包皮的体外制剂可使该器官松弛。相比之下，注射与APGWamide共定位在60%的rAL神经元中的神经肽芋螺加压素，并未诱导出任何与雄性性行为相关的行为。这些结果表明，rAL的神经元可以在电活动期间通过释放APGWamide诱导阴茎包皮外翻，就像在雄性交配时发生的那样。
