Schneider R J
Laboratory of Neuropsychology, National Institute of Mental Health, Bethesda, MD 20892.
Exp Brain Res. 1990;83(1):105-14. doi: 10.1007/BF00232198.
Metal microelectrodes were used to record extracellular potentials from single cells in the four cytoarchitectural areas 3a, 3b, 1 and 2 of the representation of the lower body of the postcentral gyrus of Macaca mulatta monkeys. The animals were paralyzed and artificially respirated while remaining awake. Non-noxious natural stimuli were employed to determine response characteristics, like the submodality, of cells. After recording from a series of normal animals, spinal cord lesions of the dorsal funiculus, were surgically performed at cervical or high thoracic spinal levels. The animals were allowed to recover, and the above-mentioned cell characterization procedures were performed. After the recording, animals were humanely sacrificed and histological reconstructions of the penetrations and the spinal lesions were made. In the postcentral gyrus of normal animals, cells in cytoarchitectural areas 3b and 1 responded predominantly to cutaneous stimuli while cells in areas 3a and 2 responded predominantly to deep stimuli. Responses to displacement of hairs were only recorded in the predominantly cutaneous areas. In these areas in animals with dorsal funiculus transections at cervical or high thoracic spinal cord levels, many fewer cells responded to somatosensory stimulation than in the same areas in normal animals. There were no longer any responses to hair displacement stimuli. In this lower body region, responses to cutaneous stimuli and responses to some deep stimuli were reduced. Cortical areas 3b and 1, that normally showed responses predominantly to cutaneous stimuli, had an increased percentage of responses to deep stimuli. Cells that did not respond to our somatic stimuli but that had a spontaneous firing pattern were found in the first somatic sensory cortex (SI). We conclude that at rostral spinal levels, the dorsal funiculus contains all of the information about hair displacement stimuli of the lower body that projects to the first somatic sensory cortex as well as much information from cutaneous receptors and some from deep receptors on the body surface. Temporal information as well as precise receptive field demarkation is also supplied to SI cells by the dorsal funiculus.
金属微电极被用于记录恒河猴中央后回下体代表区四个细胞构筑区（3a、3b、1和2区）单个细胞的细胞外电位。动物处于清醒状态，同时进行麻痹和人工呼吸。采用无害的自然刺激来确定细胞的反应特性，如亚模式。在对一系列正常动物进行记录后，在颈段或高位胸段脊髓水平进行背侧索脊髓损伤手术。让动物恢复后，进行上述细胞特征描述程序。记录完成后，对动物实施安乐死，并对穿刺部位和脊髓损伤进行组织学重建。在正常动物的中央后回中，细胞构筑区3b和1区的细胞主要对皮肤刺激有反应，而3a和2区的细胞主要对深部刺激有反应。对毛发位移的反应仅在主要的皮肤区域记录到。在颈段或高位胸段脊髓水平进行背侧索横断的动物的这些区域中，对体感刺激有反应的细胞比正常动物同一区域中的少得多。对毛发位移刺激不再有任何反应。在这个下体区域，对皮肤刺激的反应和对一些深部刺激的反应都减少了。通常主要对皮肤刺激有反应的皮质区3b和1区，对深部刺激的反应百分比增加。在第一体感皮层（SI）中发现了对我们的躯体刺激无反应但有自发放电模式的细胞。我们得出结论，在脊髓头端水平，背侧索包含了所有投射到第一体感皮层的关于下体毛发位移刺激的信息，以及来自皮肤感受器的许多信息和一些来自体表深部感受器的信息。背侧索还向SI细胞提供时间信息以及精确的感受野划分。
