FUNCTIONAL ORGANIZATION OF THE NERVUS TERMINALIS

终神经(NT)是连接周围神经的脑神经 嗅觉结构与大脑的关系。它最多只能进入大脑 中线前点，有时被称为脑神经 NT神经存在于所有脊椎动物群体中，包括 是人类唯一一条功能未知的脑神经。光纤和 NT神经及其神经节的细胞含有黄体生成素(LHRH) 释放荷尔蒙)间接控制性腺功能的多肽 而且，现在看来，它还影响男性和 雌性啮齿动物和其他物种。NT神经在脑内连接 到一个与生殖控制有关的地区，有证据表明 NT可能影响生殖行为的哺乳动物和鱼类 生理学。因此，NT可能会对来自其他生物的化学信使做出反应 通过将LHRH传递到大脑或大脑中的个人(信息素) 血管。我们正在研究板肌的NT神经和神经节。 鱼是一个离散的实体，因此可以在没有 来自其他神经结构的干扰。我们已经证明了 神经节细胞的神经活动受到强直性抑制 神经节似乎被乙酰胆碱兴奋，而被 去甲肾上腺素。间接证据表明这些细胞就是LHRH细胞， 其中许多将轴突集中发送到大脑。初步 证据表明，这些细胞中的一些可能是由来自 NT神经与鼻子的联系。显然，另一个细胞群 含有不同的多肽，被乙酰胆碱抑制，还 集中进行项目。我们提出了一种用于NT的试探性神经回路 神经节和NT功能的工作假说：NT神经节 是前脑LHRH网络的前哨，充当接口 化学感官对生殖的影响。在这里，我们提出一种 NT神经节的暂定神经回路和一个工作假说 NT功能：NT神经节是前脑的前哨 建议电路(A)使用示踪材料标记投影以 确定了神经节中的细胞类型和抑制来源 大脑；以及(B)通过记录已识别的细胞对 神经递质和神经肽以及中枢和中枢神经传入 周围神经干。此外，工作假说将是 通过测试系统(A)对以下类别的化学敏感性进行检查 已知在其他鱼类中作为信息素的化学物质和(B)通过测试NT 趋化细胞的标志物；LHRH(和其他 多肽)进入大脑和脑循环将被调查 通过收集已在其中刺激切除的NT的介质 在体外释放多肽，或通过采集血液和脑脊液后 活体刺激NT神经。通过这些手段，我们希望确定 脑神经存在于人类的脑神经的原始功能，其 功能目前未知，并演示了电路和神经 在我们的动物模型中，这一功能的基础机制。

The nervus terminalis (NT) is a cranial nerve connecting the peripheral olfactory structures with the brain. It enters the brain at the most anterior midline point, and is sometimes called "called" "cranial nerve zero". The NT nerve is present in all vertebrate groups, including humans and is the only cranial nerve of unknown function. Fibers and cells in the NT nerve and its ganglion contain LHRH (luteinizing-hormone releasing-hormone) a peptide that indirectly controls gonadal functions and, it now appears, also influences reproductive behavior of male and female rodents and other species. The NT nerve connects within the brain to a region concerned with reproductive control and there is evidence in mammals and fish that NT may influence reproductive behavior and physiology. Thus, NT may respond to chemical messengers from other individuals (pheromone) by delivering LHRH into the brain or the cerebral blood vessels. We are studying the NT nerve and ganglion in elasmobranch fish where it is a discrete entity and can thus be studied without interference from other neural structures. We have demonstrated that neural activity of cells in the ganglion is tonically suppressed by ganglion appear to be excited by acetyl choline and suppressed by norepinephrine. Indirect evidence suggests these are the LHRH cells, many of which send their axons centrally towards the brain. Preliminary evidence suggests some of these cells may be excited by neural input from the NT nerve connection with the nose. Another cell group, apparently containing a different peptide, is suppressed by acetyl choline and also projects centrally. We propose a tentative neural circuit for the NT ganglion and a working hypothesis for NT function: that the NT ganglion is an outpost of the forebrain LHRH network and serves as an interface for chemosensory influences on reproduction. Here we propose a tentative neural circuit for the NT ganglion and a working hypothesis for NT function: that the NT ganglion is an outpost of the forebrain suggested circuit (a)using tracer materials to label the projections to identified cell types in the ganglion and of sources of suppression in the brain; and (b) by recording responses of identified cells to neurotransmitter and neuropeptides and to neural input from central and peripheral nerve trunks. Further, the working hypothesis will be examined by testing the chemosensitivity of the system (a) to classes of chemicals known to act as pheromone in other fish and (b) by testing NT markers for chemoreceptive cells; The proposed release of LHRH (and other peptides) into the brain and cerebral circulation will be investigated by collecting medium in which the excised NT has been stimulated to release peptides in vitro, or by collecting blood and CSF after stimulation of the NT nerve in vivo. By these means we hope to identify the original function of a cranial nerve, present in humans, whose function is currently unknown and to demonstrate the circuits and neural mechanisms which underlie that function in our animal model.