Spinocervical tract neurons responsive to light mechanical stimulation of the raccoon forepaw.
Spinocervical tract neurons responsive to light mechanical stimulation of the raccoon forepaw.
复制标题
脊髓颈束神经元对浣熊前爪的光机械刺激有反应。
DOI：
10.1152/jn.1989.61.1.138
复制
发表时间：
1989
影响因子：
2.5
通讯作者：
PubolsJr,BH
中科院分区：
文献类型：
--
作者：
Hirata,H;PubolsJr,BH
1. 在戊巴比妥钠麻醉的貉中，研究了45个反向识别的脊髓束（SCT）神经元对前爪无毛表面光机械刺激的反应。另外7个神经元位于前肢多毛皮肤上的外周感受野（RFs）， 3个神经元具有深部感受野。2. 组织学证实所有记录位点均位于C6-T1脊髓节段的Rexed椎板III和IV内。55个神经元的反向传导速度在8.3 ~ 64.2 m/s之间。3. 具有无毛皮肤RFs的单位根据其对维持的机械刺激的反应分为快速适应（n = 39）和缓慢适应（n = 6）。在测试的11个细胞中，2个对有害刺激表现出增强的反应，并被归类为多接受性。4. 手指上的射频区域（范围= 0.4-45.0 mm2）明显小于手掌上的射频区域（范围= 5.6-76.0 mm2），其大小与之前报道的浣熊楔形核细胞中的射频区域相当（32）。5. 根据位移斜坡刺激时瞬时尖峰频率与斜坡速度、陡函数（由幂函数指数值定义）、平函数和不连续函数的关系，RA神经元可分为三类；SA神经元分为连续和不连续两类。6. 这些结果与之前的研究结果相结合，得出了两个主要结论：1)浣熊和灵长类动物的脊髓-颈-丘脑系统彼此之间的相似性比猫和灵长类动物的脊髓-颈-丘脑系统更相似；2)浣熊SCT从前爪无毛皮肤传递光机械刺激特征信息的能力至少与背柱-内侧神经系统的神经元一样精确。
1. The extracellular activity of 45 antidromically identified spinocervical tract (SCT) neurons responsive to light mechanical stimulation of the glabrous surfaces of the forepaw was examined in raccoons anesthetized with pentobarbital sodium. An additional seven neurons had peripheral receptive fields (RFs) located on hairy skin of the forelimb, and three had deep RFs. 2. All recording sites were histologically verified as falling within Rexed's laminae III and IV in spinal cord segments C6-T1. Antidromic conduction velocities of the 55 neurons ranged between 8.3 and 64.2 m/s. 3. Units with glabrous skin RFs were classified according to their response to a maintained mechanical stimulus as either rapidly adapting (n = 39) or slowly adapting (n = 6). Of 11 cells tested, 2 displayed enhanced responses to noxious stimuli and were classed as multireceptive. 4. RF areas were significantly smaller on digits (range = 0.4-45.0 mm2) than on palm pads (range = 5.6-76.0 mm2), and comparable in size to RF areas previously reported in raccoon cuneate nuclear cells (32). 5. RA neurons fell into three distinct categories with respect to the relationship between instantaneous spike frequency during displacement ramp stimulation, and ramp velocity, steep functions (as defined by the value of power function exponents), flat functions, and discontinuous functions; SA neurons fell into two categories, continuous, and discontinuous. 6. The results, in conjunction with those of previous studies, lead to two major conclusions: 1) raccoon and primate spinocervicothalamic systems are more similar to each other than either is to that of the cat and 2) the ability of the raccoon SCT to convey information from the glabrous skin of the forepaw regarding characteristics of light mechanical stimuli is at least as precise as that of neurons of the dorsal column-medial lemniscal system.