Development of an in vitro preparation for analysis of central mechanisms controlling mastication

开发用于分析控制咀嚼的中枢机制的体外制剂

基本信息

批准号：
09557143
负责人：
NAKAMURA Yoshio
金额：
$ 6.53万
依托单位：
Tokyo Medical and Dental University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09557143/
关键词：
Mastication Sucking Rhtyhm generator in vitro Brainstem Mouse Trigeminal motoneuron Postnatal development

项目摘要

The purpose of this study was to develop an in vitro brainstem preparation isolated from adult animals, in which masticatory movements can be induced. In the first year of this study, we succeeded to induce rhythmical reciprocal activities in masseter and digatric muslces by repetitive stimulation of the pontine pyramidal tract in an in vitro brainstem preparation kept alive by O_2 supply with an artificial cerebraospinal fluid (ACSF) saturated with 95% 0_2-5% CO_2 via the vascular system and diffusion from the perfusing ACSF in the rcording chamber. However, the necessity of perfusion of the brainstem via the vascular system was the critical fault of this preparation. To overcome this drawback and to keep the in vitro brainstem alive by diffusion of 0_2 solely from the ACSF in the recording chamber, it was necessary to reduce the size of the brainstem prparation by isolating only the portion of the brainstem containing the minimum structure essential for the masticatory rhythm generation in the trigeminal motoneurons (V MNs). In the second year, accordingly, we studied (1) whether there is a single rhythm generator or separate genarators for the V, facial (VII) and hypoglossal (XII) MNs, and (2) the localization of the rhythm generator of the V MNs. Bath application of NMDA to the isolated brainstem of the newborn mouse induced rhythmical activities in V, VII and XII MNs with cycle times diferent from one another, and these rhythmical activities persisted after transection of the brainstem between the V and VII nerves, and between the VIl and XII nerves. The results indicate that separate rhythm generators for V VII and XII MNs are located segmentally at the V motor, VII and XII nuclei, respectively. This finding provides a basic data for developing an in vitro block preparation containing only the rhythm gnerator for the V MNs.

这项研究的目的是开发从成年动物中分离出的体外脑干制剂，其中可以诱导咀嚼运动。在这项研究的第一年，我们通过在体外脑干制备物中重复刺激脑桥锥体束，成功诱导咬肌和二肌有节奏的相互活动，该体外脑干制备物通过供应 O_2 和饱和 95 的人工脑脊液 (ACSF) 保持活力。 % 0_2-5% CO_2 通过血管系统并从记录室中的灌注 ACSF 扩散。然而，通过血管系统灌注脑干的必要性是该制剂的关键缺陷。为了克服这一缺点并通过仅从录制室中的ACSF扩散0_2来保持体外脑干的生存，必须通过仅隔离包含最小结构的最小结构必不可少的部分来减少脑干的大小。三叉神经运动神经元（V MN）中咀嚼节律的产生。因此，在第二年，我们研究了（1）V、面部（VII）和舌下（XII）MN是否有单个节律发生器或单独的发生器，以及（2）V节律发生器的定位MN。将 NMDA 浸入新生小鼠的离体脑干中，可诱导 V、VII 和 XII MN 出现节律性活动，其周期时间彼此不同，并且这些节律性活动在 V 和 VII 神经之间以及神经之间的脑干横断后仍持续存在。 VII 和 XII 神经。结果表明，V VII 和 XII MN 的单独节律发生器分别分段位于 V 运动核、VII 和 XII 核处。这一发现为开发仅包含 V MN 节律发生器的体外块制剂提供了基础数据。