MECHANISMS OF TRIGEMINAL PRIMARY AFFERENT ARBOR FORMATION

三叉神经初级传入轴的形成机制

• 批准号: 3753688
• 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/3753688
• 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.

此应用程序用于a)检查发芽响应 未损伤和受损的三叉神经初级传入神经元 新生儿周围神经损害及b)部分机制的研究 这在病变诱导的中央终末的产生中可能是重要的 乔木异常。为了实现这些目标，我们提出了以下建议 三个实验：1)未损伤的三叉神经初级神经的潜能 传入神经通过萌发、乔木扩张改变其中枢投射 或通过烧灼所有触觉来检查刀杆移位 神秘垫上的卵泡，C或D排的除外。 使用轴突内和细胞内标记技术，我们将确定 未受干扰的外周终末的初级传入反应 导致他们的中心目标部分丧失神经。2)我们将利用 定量电子显微镜技术研究影响 新生儿眶下神经中央终末横断术 两个小直径初级传入神经元亚集的种群 (P物质样免疫反应和抗氟酸性磷酸酶- 阳性)。通过在神经后按顺序间隔检查动物 我们将确定单位面积的航站楼数量是否 尾侧亚核的胶状质和大细胞区 保持、减少或增加(表示发芽)。3)至 确定有模式的初级传入活动在 三叉神经初级传入中枢终末的发育与维持 乔木，我们将从年月日开始将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，因此没有造成任何营养物质运输的明显中断 对关于受损和有害物质反应的信息重要的物质 未受损伤的神经元对损伤引起的部分脑区去传入的影响 三叉神经系统。这一知识在临床上有重要的好处 除了它的价值之外，还有助于我们理解 体感发育。