STUDIES OF MEDULLARY NEURONS IMPLICATED IN NOCICEPTION

与伤害感受有关的髓质神经元的研究

基本信息

批准号：
3400579
负责人：
WARREN E FOOTE
金额：
$ 13.37万
依托单位：
MASSACHUSETTS GENERAL HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
1983
资助国家：
美国
起止时间：
1983-12-01 至 1987-11-30
项目状态：
已结题

项目摘要

Pontomedullary structures, particularly the raphe magnus and reticular magnocellularis, have been shown to contribute an inhibitory influence to dorsal horn neurons via the dorsolateral fasciculus. This caudal brainstem mechanism is thought to play a major role in modulating the ascending transmission of nociceptive information. Though raphe-spinal and reticulo-spinal efferents have been well characterized, the nature of afferent inputs to the medulla which activate, or otherwise influence such a descending analgesic mechanism are poorly understood. Thus, to ascertain the afferent neurocircuitry which may be related to raphe-spinal and reticulo-spinal inhibitory mechanisms, we propose to use electrophysiological methods, combined with horseradish peroxidase labeling to: 1. describe afferent influences on raphe and adjacent magnocellularis neurons - somatosensory, mesencephalic, reticular, and spinal afferents of raphe nuclei and adjacent nucleus magnocellularis will be examined to determine the nature of their input, especially in regard to threshold latencies, summation, convergence, and interactions; 2. physiologically characterize raphe-spinal and non-spinal raphe neurons - neurons identified as raphe-spinal on the basis of antidromic activation from spinal cord, will be compared to non-spinal raphe neurons with respect to afferent input, physiological response, and location within the caudal raphe complex; 3. relate physiological responses of raphe-spinal, non-spinal raphe, and reticular neurons with their morphology, axon trajectory, and cytoarchitecture as revealed by HRP labeling - the various characterizations addressed in these studies will be used to provide a comprehensive classification of medullary neurons, particularly in terms of the cytoarchitecture of caudal medullary structures; 4. relate raphe physiology and cytoarchitecture with putative neuro-transmitter systems - an attempt will be made to determine whether the afferent responses and morphological characteristics of raphe-spinal projections can be dissociated on the basis of putative neurotransmitter systems. Immunocytochemistry methods will be used to stain for serotonin and substance P in intracellularly recorded raphe and magnocellularis cells labeled with HRP. These data may offer new insight into transmitter mechanisms responsible for the descending inhibitory action of medullary neurons.

pontomedullary结构，尤其是Raphe Magnus和网状结构巨细胞已显示出对背外侧筋膜背喇叭神经元。这个尾脑干人们认为机制在调节上升方面起着重要作用伤害性信息的传输。虽然raphe spinal和网状脊柱受发的表征已经很好，激活或以其他方式影响这种延髓的传入输入降临的镇痛机制知之甚少。因此，确定可能与Raphe-Spinal和网状脊柱抑制机制，我们建议使用电生理方法，结合辣根过氧化物酶标记至：1。描述对raphe和相邻磁细胞的传入影响神经元 - 体感，中脑，网状和脊柱传入将检查raphe核和邻近核核细胞核心。确定其输入的性质，尤其是关于阈值潜伏期，总和，收敛和互动； 2。在生理上表征raphe脊柱和非脊髓raphe神经元 - 已鉴定的神经元根据脊髓抗肿瘤激活的raphe脊髓，将相对于传入尾raphe内的输入，生理反应和位置复杂的; 3。相关的Raphe-Spinal，非脊柱的生理反应 raphe和网状神经元及其形态，轴突轨迹和 HRP标签揭示的细胞结构 - 各种这些研究中涉及的特征将用于提供髓质神经元的全面分类，特别是尾骨结构的细胞结构； 4 具有假定的神经递质系统的生理和细胞结构 - 将尝试确定传入的响应和是否有 Raphe脊柱投影的形态学特征可以是根据推定的神经递质系统解离。免疫细胞化学方法将用于染色5-羟色胺和物质在细胞内记录的Raphe和大细胞细胞中用HRP标记。这些数据可能会为发射器提供新的见解负责髓样降低抑制作用的机制神经元。