AN ELECTROPHYSIOLOGICAL STUDY OF SINGLE SOMATOSENSORY NEURONS IN RAT GRANULAR CORTEX SERVING THE LIMBS - A LAMINAR ANALYSIS
AN ELECTROPHYSIOLOGICAL STUDY OF SINGLE SOMATOSENSORY NEURONS IN RAT GRANULAR CORTEX SERVING THE LIMBS - A LAMINAR ANALYSIS
复制标题
DOI：
10.1152/jn.1988.60.2.703
复制
发表时间：
1988-08-01
影响因子：
2.5
通讯作者：
LAMOUR, Y
中科院分区：
文献类型：
--
作者：
DYKES, RW;LAMOUR, Y
1.记录了545个神经元的躯体感觉颗粒皮层的麻醉Sprague-Dawley大鼠。在这个样本中，32%是自发活动的。活动神经元在皮层的分布并不均匀，但最常见的是在第五层。最高的平均自发放电频率也被发现在这一层。自发活动率最低的细胞位于正上方和正下方。自发活动神经元的一个子集的特点是异常高的放电频率调制的躯体刺激。2.在颗粒皮层的534个神经元中，只有25.8%的神经元能被躯体刺激激活。只有9.4%的人有皮肤感受野，2.4%的人接受深层输入。其余的（14.0%）是由更高强度的刺激驱动的，不能明确分类为皮肤或深部。50个具有皮肤感受野的神经元位于皮层的中间三分之一，并且那些具有最大感受野的神经元被发现最浅。由躯体刺激驱动的神经元最常被发现在Vb层，其中44.5%的样本证实在Vb层可以被兴奋。3.缺乏明显的躯体输入的神经元的大部分是由于使用离子电渗给药谷氨酸，这使得许多无反应的神经元的检测。使用一氧化二氮和氟烷作为麻醉剂并没有降低这一比例。4.在后肢颗粒皮质的内侧和喙侧边缘发现了仅由深部输入激活的神经元，这表明在该物种中深部和皮肤输入可能是分离的。5.施加到脚垫的电刺激激活的神经元的样本不同于由自然躯体刺激驱动的神经元的深度，自发活动，躯体输入的概率，以及由锥体束激活的概率。6.锥体束神经元往往位于Vb层，自发活动，并有证据表明，躯体输入，虽然大多数需要相对强烈的刺激被兴奋。从锥体束突触激活的其他神经元位于锥体束神经元的正上方和正下方的层中。根据动作电位潜伏期、动作电位形状和对乙酰胆碱的敏感性将这些细胞分为两组。
1. Recordings were made from 545 neurons in somatosensory granular cortex of anesthetized Sprague-Dawley rats. Of this sample, 32% were active spontaneously. Active neurons were not distributed uniformly throughout cortex but were most common in layer V. The highest mean spontaneous discharge frequency also was found in this layer. Cell with the lowest rates of spontaneous activity were located immediately above and below. One subset of spontaneously active neurons was characterized by an unusually high discharge frequency modulated by somatic stimulation. 2. Only 25.8% of the 534 neurons tested in granular cortex could be activated by somatic stimuli. Only 9.4% had cutaneous receptive fields, and 2.4% received deep inputs. The remainder (14.0%) were driven by higher intensity stimuli and could not be classified unequivocally as either cutaneous or deep. The 50 neurons with cutaneous receptive fields were located in the middle third of the cortex, and those with the largest receptive fields were found most superficially. Neurons driven by somatic stimuli were found most frequently in layer Vb, where 44.5% of the sample confirmed histologically to be in layer Vb could be excited. 3. The large proportion of neurons lacking demonstrable somatic inputs was attributed to the use of iontophoretically administered glutamate, which allowed the detection of many unresponsive neurons. This proportion was not reduced by the use of nitrous oxide and halothane as an anesthetic. 4. Neurons activated only by deep inputs were found on the medial and rostral edge of the hindlimb granular cortex, suggesting that deep and cutaneous inputs may be segregated in this species. 5. Electrical stimuli applied to the foot pads activated a sample of neurons differing from those driven by natural somatic stimuli in terms of depth, spontaneous activity, probability of somatic input, and probability of activation by the pyramidal tract. 6. Pyramidal tract neurons tended to be located in layer Vb, were active spontaneously, and had evidence of somatic inputs, although most required relatively intense stimuli to be excited. Other neurons activated synaptically from the pyramidal tract were located in the layers immediately above and below the pyramidal tract neurons. These cells were divided into two groups on the basis of action-potential latency, action-potential shape, and sensitivity to acetylcholine.