Norekyan T P, Satterlie R
Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, Moscow.
Neurosci Behav Physiol. 1993 Jan-Feb;23(1):11-23. doi: 10.1007/BF01182633.
The neurons of the cerebral ganglia controlling the movements of the hunting apparatus of the predatory pelagic pteropod mollusc, Clione limacina, are described in detail. A large group of high-threshold, electrically interconnected neurons, A, was identified, the impulse activity of which leads to the opening of the skin folds and the forward ejection of the hunting tentacles of the clione. Group B neurons which exhibit a constant background activity and which receive powerful inhibitory inputs from the A cells, conversely, induce the contraction and the withdrawal of the hunting tentacles into the head. The third group, are the C neurons, the impulse activity of which leads to the drawing together of the skin folds covering the hunting apparatus. The effect of such mediators as serotonin, dopamine, and gamma aminobutyric acid acid on the identified neurons was investigated. Serotonin depolarizes both A and B neurons, but the activation of the hunting apparatus appears to be an integrated effect: the activated A neurons inhibit the B neurons due to powerful IPSP, interrupting the direct excitatory effect of serotonin. Dopamine in various concentrations exerts the opposite effect: at low concentrations only B cells are activated and the tentacles are withdrawn into the head; at high concentrations the A neurons begin to operate; these neurons inhibit the B cells and activate the hunting apparatus. GABA exerts an integral, well-coordinated effect on the neurons controlling the movements of the hunting apparatus, and effect which is directed toward the activation of hunting behavior: it depolarizes-activates A neurons and hyperpolarizes-inhibits B and C neurons.
详细描述了控制掠食性远洋翼足类软体动物——海若螺（Clione limacina）捕食器官运动的脑神经节神经元。识别出一大组高阈值、电互连的神经元A，其冲动活动会导致皮肤褶皱张开以及海若螺的捕食触手向前弹出。相反，神经元B组表现出持续的背景活动，并从A细胞接收强大的抑制性输入，可诱导捕食触手收缩并缩回头部。第三组是C神经元，其冲动活动会导致覆盖捕食器官的皮肤褶皱合拢。研究了血清素、多巴胺和γ-氨基丁酸等介质对已识别神经元的影响。血清素使A和B神经元都去极化，但捕食器官的激活似乎是一种综合效应：被激活的A神经元由于强大的抑制性突触后电位抑制B神经元，中断了血清素的直接兴奋作用。不同浓度的多巴胺产生相反的效果：低浓度时仅B细胞被激活，触手缩回头部；高浓度时A神经元开始起作用；这些神经元抑制B细胞并激活捕食器官。γ-氨基丁酸对控制捕食器官运动的神经元产生整体、协调良好的作用，该作用旨在激活捕食行为：它使A神经元去极化并激活，使B和C神经元超极化并抑制。
