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Category:Primary somatosensory cortex
Abbrev S1, Sm1, SSp  +
CurationStatus uncurated  +
CytoDefiningCriteria (Welker, 1970, rat): The physiological bo (Welker, 1970, rat): The physiological boundaries of SmI coincided with a cytoarchitectural area which exhibited a prominent granular IVth layer. Distinct multicellular aggregates were found within layer IV of the facial sinus hair area. The location of these aggregates, their number (which was similar to the number of facial sinus hairs), and their somatotopic arrangement suggested the hypothesis that each aggregate is a functional unit which receives somatic sensory information from a single, specific sinus hair. In most regions of SmI there is a very prominent layer IV composed of small, densely packed, darkly stained granular cells. The distinctiveness of layer IV is further enhanced by the paleness of layer Va just below it. In most areas of SmI layer Vb contains pyramidal cells of medium size. The medial part of SmI, however, is distinguished by many more relatively large cells in layer Vb (Fig.5) relatively large cells in layer Vb (Fig.5)
Definition (Chapin & Lin, 1984, rat): the region (Chapin & Lin, 1984, rat): the region considered as the SI cortex is not a cytoarchitecturally homogeneous structure but consists instead of a patchwork array of areas containing dense aggregations of layer IV granule cells, surrounded by granule-cell-sparse regions. As was shown by Welker ('71,'76), and in our own mapping studies (see Fig. 3), this discontinuous pattern of granular, or koniocortical, zones contains within itself a map of the rat's cutaneous periphery. There are clear subtypes within this cytoarchitectural subregion, notably including the "granular aggregate" type of cytoarchitecture characteristic of the paw, limb, and mystacial vibrissae areas, and the "barrel-field" type (originally described by Woolsey and Van der Loos, '70) seen in the nose and perioral regions. In the mouse, but not the rat, such barrels also cover the whole whisker representation (Welker and Woolsey, '74). representation (Welker and Woolsey, '74).
Has default formThis property is a special property in this wiki. PONS brain region  +
Id nlx_143551  +
Is part of Parietal cortex +, Somatosensory system +
Label Primary somatosensory cortex  +
Modification dateThis property is a special property in this wiki. 2 February 2015 03:34:41  +
ModifiedDate 2 February 2015  +
Page has default formThis property is a special property in this wiki. PONS brain region  +
SuperCategory Regional part of brain  +
TomoDefiningCriteria In humans, located posterior to the centra In humans, located posterior to the central sulcus in the postcentral gyrus of the parietal lobe (Kandel, Schwarz and Jessel, Principles of Neural Science, ed 4, pg 326). (Welker, 1970): the most medial boundary of SmI extended to within 2-3 mm from the midline dorsally, and the most lateral to 0.5-1.0 mm above the rhinal sulcus. In the 637 penetrations made within this region (Fig. 1B), responses were obtained from only contralateral receptive fields by gentle mechanical stimulation of peripheral body surfaces. Nil penetrations were defined as those in which no responses were obtained to such stimulation, or in which responses were obtained from either a bilateral peripheral field indicating that the electrode was in SmII, or from auditory stimulation. There were 115 nil penetrations that served to delineate the external limiting boundaries of SmI (Fig. 1B). Although the vascular pattern varied among the animals, SmI projections were always located primarily in the area where the ascending frontal, parietal,and parietotemporal branches of the middle cerebral artery diverged from the parent vessel (Fig. 1A). diverged from the parent vessel (Fig. 1A).
Categories Regional part of brain
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Ventral posterior nucleus + EfferentProjections
Barrel cortex +, Primary somatosensory cortex lamina VI + Is part of
Resource:Expression Atlas of the Marmoset + Keywords


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