Topography of recurrent inhibitory postsynaptic potentials between individual motoneurons in the cat.
Topography of recurrent inhibitory postsynaptic potentials between individual motoneurons in the cat.
复制标题
猫个体运动神经元之间反复抑制突触后电位的地形图。
DOI：
10.1152/jn.1994.72.1.214
复制
发表时间：
1994
影响因子：
2.5
通讯作者：
Hamm,TM
中科院分区：
文献类型：
--
作者：
McCurdy,ML;Hamm,TM
1.复发性抑制性突触后电位（RIPSPs）的幅度进行了检查，在成对的腰骶运动神经元，由一个已知的距离分开，并确定由逆行刺激的肌肉神经。通过注射去极化电流脉冲刺激一个运动神经元，记录第二个运动神经元的突触后反应并取平均值。许多运动神经元的输入电阻，基强度和传导速度进行了测定。大多数运动神经元支配伸肌。2.记录到的RIPSP值高达-283 microV，但大多数在-10和-40 microV之间。来自一个池的单个运动神经元的RIPSPs分布到几个异源运动核，并且具有与同源RIPSPs相当的幅度范围。3.发现RIPSP振幅的特定空间分布，其中最大RIPSP振幅（> 40 microV）发生在位于受刺激运动神经元的+/-1.4 mm内的运动神经元中。所有运动神经元对的RIPSP振幅与运动神经元间的距离呈显著相关。这种相关性也被发现在个别群体的运动神经元对，支配腓肠肌外侧，内侧，前中股二头肌，或比目鱼肌。4. RIPSP振幅对运动神经元种类（运动神经元支配的特定肌肉）的依赖性不如RIPSP振幅对地形的依赖性明显。汇集所有的运动神经元物种密切的运动神经元对表明，RIPSPs测量homembryonic运动神经元对的幅度大于RIPSPs测量heterembryonic对。此外，在所有异源组合中，股二头肌前中段或腓肠肌外侧运动神经元的同源RIPSP均大于异源RIPSP。然而，同源和异源RIPSPs没有显着差异时，异源对仅限于个别组合的物种。这些研究结果表明，RIPSP振幅内的一组运动核相互联系的复发性抑制是依赖于在某些情况下的运动神经元的物种，但这种效果是不太重要的地形上RIPSP振幅的影响。5.这些结果表明，在运动神经元池，支配后肢伸肌的复发性抑制有很强的地形组织，这样最强的复发性抑制是由每个运动神经元在一个有限的rostrocaudal区，包括homelines和heterelines运动核。这表明，复发性抑制是有组织的，用于控制参与共同运动活动的几个运动核团，以及调节单个运动池内的活动。
1. The amplitude of recurrent inhibitory postsynaptic potentials (RIPSPs) was examined in pairs of lumbosacral motoneurons that were separated by a known distance and were identified by antidromic stimulation of muscle nerves. One motoneuron was stimulated by injecting depolarizing current pulses, and postsynaptic responses were recorded and averaged in the second motoneuron. Input resistance, rheobase, and conduction velocity were determined for many motoneurons. Most motoneurons innervated extensor muscles. 2. RIPSP values as large as -283 microV were recorded, but most were between -10 and -40 microV. RIPSPs from individual motoneurons of a pool are distributed to several heteronymous motor nuclei and have a range of amplitudes comparable with homonymous RIPSPs. 3. A specific spatial distribution of RIPSP amplitudes was found whereby the largest RIPSP amplitudes (> 40 microV) occurred in motoneurons located within +/- 1.4 mm of the stimulated motoneuron. A significant correlation was found between RIPSP amplitude and the distance between motoneurons for all motoneuron pairs. This correlation was also found within individual groups of motoneuron pairs that innervate the lateral gastrocnemius, medial gastrocnemius, anterior-middle biceps femoris, or soleus muscles. 4. The dependency of RIPSP amplitude on the motoneuron species, which is the particular muscle a motoneuron innervates, is less distinct than the dependency of RIPSP amplitude on topography. Pooling all motoneuron species of close motoneuron pairs indicated that RIPSPs measured in homonymous motoneuron pairs were greater in amplitude than RIPSPs measured in heteronymous pairs. In addition, homonymous RIPSPs of anterior middle biceps femoris or lateral gastrocnemius motoneurons were greater than heteronymous RIPSPs of those motoneurons in all heteronymous combinations. However, homonymous and heteronymous RIPSPs were not significantly different when heteronymous pairs were restricted to individual combinations of species. These findings indicate that RIPSP amplitudes within a set of motor nuclei interconnected by recurrent inhibition are dependent in some cases on the species of motoneurons, but this effect is less important than the effect of topography on RIPSP amplitude. 5. These results indicate that recurrent inhibition in motoneuron pools that innervate hindlimb extensor muscles has a strong topographic organization, such that the strongest recurrent inhibition is produced by each motoneuron in a restricted rostrocaudal zone that includes both homonymous and heteronymous motor nuclei. This suggests that recurrent inhibition is organized for the control of several motor nuclei engaged in common motor activity as well as regulation of activity within individual motor pools.