MECHANISMS OF TRIGEMINAL PRIMARY AFFERENT ARBOR FORMATION

三叉神经初级传入轴的形成机制

• 批准号: 3775806
• 负责人: WILLIAM E RENEHAN
• 金额: --
• 依托单位: SAINT LOUIS UNIVERSITY
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/3775806
• 关键词: acid phosphatase; afferent nerve; brain stem; central nervous system disorders; ganglion cell; ganglionic blocking agents; hair; innervation; laboratory rat; microelectrodes; neurotoxins; newborn animals; stimulus /response; substance P; tetrodotoxin; trigeminal nerve

This application is designed to a) examine the sprouting response of undamaged and damaged trigeminal primary afferent neurons following neonatal peripheral nerve lesions and b) to study some of the mechanisms which may be important in the generation of lesion-induced central terminal arbor abnormalities. To accomplish these goals we propose the following three experiments: 1) The potential of undamaged trigeminal primary afferents to alter their central projections via sprouting, arbor expansion or arbor displacement will be examined by cauterizing all vibrissa follicles of the mystical pad with the exception of those in row C or D. Using intraaxonal and intracellular labeling techniques, we will determine the response of primary afferents with undisturbed peripheral terminations to partial denervation of their central target. 2) We will utilize quantitative electron microscopic techniques to investigate the impact of neonatal infraorbital (IO) nerve transection on the central terminal populations of two subsets of small diameter primary afferent neurons (substance P-like immunoreactive and fluoride resistant acid phosphatase- positive). By examining animals at sequenced intervals after the nerve injury we will determine if the number of terminals per unit area of the substantia gelatinosa and magnocellular region of subnucleus caudalis is maintained, decrease or increased (indicative of sprouting). 3) To determine the importance of patterned primary afferent activity in the development and maintenance of trigeminal primary afferent central terminal arbors, we will expose the IO nerve to tetrodotoxin beginning on the day of birth. This will inhibit primary afferent activity without transecting the nerve, thus causing no apparent disruption in the transport of any trophic substances important to information regarding the response of damaged and undamaged neurons to lesion-induced deafferentation of a portion of the trigeminal system. This knowledge has important clinical benefits in addition to its value as a contribution to our understanding of somatosensory development.

此应用程序的目的是a）检查发芽反应的 未受损和受损的三叉神经初级传入神经元 新生儿周围神经病变和B）研究的一些机制 这可能在损伤诱导的中央终末的产生中起重要作用 乔木异常 为了实现这些目标，我们提出以下建议 三个实验：1）未受损的三叉神经初级电位 传入神经通过萌芽、乔木扩张改变其中枢投射 或通过烧灼所有触须检查刀轴位移 神秘垫的毛囊，除了C排或D排的毛囊。 使用轴突内和细胞内标记技术，我们将确定 外周末梢未受干扰时初级传入神经的反应 导致他们的中心目标部分失去神经 2)我们将利用 定量电子显微镜技术，以调查的影响 新生儿眶下（IO）神经切断中央终端 小直径初级传入神经元的两个子集的群体 （P物质样免疫反应性和耐氟酸性磷酸酶- 正）。 通过对动物进行神经刺激后的间隔检查， 伤害我们将确定单位面积的端子数量是否 胶状质和尾侧亚核大细胞区 减少或减少，增加或减少。 3)到 确定模式初级传入活动的重要性 三叉神经初级传入中枢终末的发育和维持 树木，我们将从当天开始将IO神经暴露于河豚毒素 出生 这将抑制初级传入活动，而不会切断 神经，因此在任何营养物质的运输中不会引起明显的中断 物质的重要信息， 未受损的神经元损伤诱导的一部分的传入阻滞， 三叉神经系统 这一知识具有重要的临床益处， 除了它的价值，作为对我们理解的贡献， 躯体感觉发育