Watson W H, Nash A, Lee C, Patz M D, Newcomb J M
Department of Biological Sciences, University of New Hampshire, Durham, NH 03824, USA.
Department of Biology and Health Science, New England College, Henniker, NH 03242, USA.
Integr Org Biol. 2020 May 29;2(1):obaa016. doi: 10.1093/iob/obaa016. eCollection 2020.
The neuropeptide small cardioactive peptide (SCP) plays an integrative role in exciting various motor programs involved in feeding and locomotion in a number of gastropod species. In this study, immunohistochemistry, using monoclonal antibodies against SCP, was used to localize SCP-like-immunoreactive neurons in the central nervous system, and map their connections to various tissues, in the nudibranch, . Approximately 28-36 SCP-like-immunoreactive neurons were identified in the brain, as well as one large neuron in each of the buccal ganglia. The neuropil of the pedal ganglia contained the most SCP-like-immunoreactive varicosities, although only a small portion of these were due to SCP-like-immunoreactive neurons in the same ganglion. This suggests that much of the SCP-like immunoreactivity in the neuropil of the pedal ganglia was from neurons in other ganglia that projected through the pedal-pedal connectives or the connectives from the cerebral and pleural ganglia. We also observed extensive SCP innervation along the length of the esophagus. Therefore, we investigated the impact of SCP on locomotion in intact animals, as well as peristaltic contractions of the isolated esophagus. Injection of intact animals with SCP at night led to a significant increase in crawling and swimming, compared to control animals injected with saline. Furthermore, perfusion of isolated brains with SCP initiated expression of the swim motor program. Application of SCP to the isolated quiescent esophagus initiated rhythmic peristaltic contractions, and this occurred in preparations both with and without the buccal ganglia being attached. All these data, taken together, suggest that SCP could be released at night to arouse animals and enhance the expression of both feeding and swimming motor programs in .
神经肽小 cardioactive 肽（SCP）在多种腹足纲动物中，对激发参与进食和运动的各种运动程序发挥着整合作用。在本研究中，使用针对 SCP 的单克隆抗体进行免疫组织化学，以定位中枢神经系统中 SCP 样免疫反应性神经元，并绘制它们与裸鳃亚目动物各种组织的连接图谱。在脑中鉴定出约 28 - 36 个 SCP 样免疫反应性神经元，以及在每个口神经节中有一个大神经元。足神经节的神经纤维网含有最多的 SCP 样免疫反应性曲张体，尽管其中只有一小部分是由于同一神经节中的 SCP 样免疫反应性神经元所致。这表明足神经节神经纤维网中的许多 SCP 样免疫反应性来自其他神经节中的神经元，这些神经元通过足 - 足连接或来自脑和胸膜神经节的连接投射而来。我们还观察到沿食管全长有广泛的 SCP 神经支配。因此，我们研究了 SCP 对完整动物运动以及离体食管蠕动收缩的影响。与注射生理盐水的对照动物相比，在夜间给完整动物注射 SCP 导致爬行和游泳显著增加。此外，用 SCP 灌注离体脑引发了游泳运动程序的表达。将 SCP 应用于离体静止食管引发了节律性蠕动收缩，并且在有和没有附着口神经节的制剂中均发生这种情况。所有这些数据综合起来表明，SCP 可能在夜间释放以唤醒动物，并增强裸鳃亚目动物进食和游泳运动程序的表达。
