Rostrocaudal gradients in the neuronal receptive field complexity in finger region of the alert monkey's postcentral gyrus

• Published in: Experimental brain research 1993, Vol.92 (3), p.360-368
• Main Authors: IWAMURA, Y, TANAKA, M, SAKAMOTO, M, HIKOSAKA, O
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Cerebral Cortex - anatomy & histology; Cerebral Cortex - cytology; Cerebral Cortex - physiology; Female; Fingers - innervation; Fingers - physiology; Fundamental and applied biological sciences. Psychology; Macaca; Male; Neurons - physiology; Sensory Receptor Cells - physiology; Skin - innervation; Skin Physiological Phenomena; Somatosensory Cortex - anatomy & histology; Somatosensory Cortex - cytology; Somatosensory Cortex - physiology; Somesthesis and somesthetic pathways (proprioception, exteroception, nociception); interoception; electrolocation. Sensory receptors; Vertebrates: nervous system and sense organs
• ISSN: 0014-4819; 1432-1106
• DOI: 10.1007/bf00229023

In the primate postcentral gyrus, the cytoarchitectonic characteristics gradually shift from those of koniocortex to more homotypical parakoniocortex along its rostrocaudal axis. To find the physiological correlates of these changes we examined a large body of data accumulated during a series of our experiments with alert monkeys. Along the rostrocaudal axis of the postcentral gyrus, we found a gradual and continuous increase in the number of neurons with converging receptive fields and those in which receptive field positions or submodalities were not determined. Deep or skin submodality neurons were dominant in area 3a or 3b respectively. The proportion of skin submodality neurons decreased gradually from area 3b to the more caudal part of the gyrus. The proportion of deep submodality neurons was almost constant from area 3b to area 2 inclusive; they were not the majority in area 2. The data are consistent with the hierarchical scheme, i.e., within the postcentral gyrus sensory information is processed from the primary sensory receiving stage to the more associative, integrative stages.