Summary
Quantitative techniques were used to demonstrate cortical layer differences in cutaneous receptive fields (RF's) in the rat SI cortex. Two- and three-dimensional (2-D and 3-D) RF maps were constructed showing the responsiveness of single neurons to standardized punctate stimulation of each of a matrix of points on the skin or the mystacial vibrissa pad. These allowed a visualization not only of the overall sizes of such RF's, but also their shape and “response profile”. Initial experiments showed that the sizes and response profiles of such RF's were similar whether they were mapped by sinusoidal mechanical vibration of skin, punctate touch, or direct intracutaneous electrical stimulation. This method was used to quantitatively determine distoproximal lengths of RF's of single units recorded at different depths in the forepaw area of the SI cortex. Plots of these RF lengths as a function of cortical depth showed that the smallest RF's were found in the granular layers (IV and deep III). RF's up to double that size were found in supragranular layers, and up to triple that size in infragranular layers. 3-D maps of RF's in the granular layers showed sharp central response peaks surrounded by very steep dropoffs to the RF boundaries. In the whisker areas, granular layer RF's were typically circular in shape and contained from 1–4 whiskers. By contrast, in supragranular layers they were often elongated in shape, and were oriented along rows or columns of whiskers. RF's in layer V resembled large, high plateaus, often supporting clearly separated peaks. RF's mapped in the fore- and hindpaw areas were similar, but, even in the granular layers, were often slightly elongated along the limb axis. In all regions of the SI, both the locations and shapes of the granular layer RF's appeared to be conserved as subsets of other more topographically heterogeneous RF's encountered elsewhere in the column. These findings may correlate with patterns of axonal connectivity in the rat SI.
Similar content being viewed by others
References
Chapin JK, Waterhouse BD, Woodward DJ (1981) Differences in cutaneous sensory response properties of single somatosensory cortical neurons in awake and halothane anesthetized rats. Brain Res Bull 6: 63–70
Chapin JK, Woodward DJ (1981) Modulation of sensory responsiveness of single somatosensory cortical cells during movement and arousal behaviors. Exp Neurol 72: 164–178
Chapin JK, Lin C-S (1984) Mapping the body representation in the SI cortex of anesthetized and awake rats. J Comp Neurol 229: 199–213
Costanzo RM, Gardner EP (1980) A quantitative analysis of responses of direction-sensitive neurons in somatosensory cortex of awake monkeys. J Neurophysiol 43: 1319–1340
Gardner EP, Costanzo RM (1980a) Spatial integration of multiplepoint stimuli in primary somatosensory cortical receptive fields of alert monkeys. J Neurophysiol 43: 420–443
Gardner EP, Costanzo RM (1980b) Neuronal mechanisms underlying direction sensitivity of somatosensory cortical neurons in awake monkeys. J Neurophysiol 43: 1342–1354
Hellweg F-C, Schultz W, Creutzfeldt OD (1977) Extracellular and intracellular recordings from cat's cortical whisker projection area: thalamocortical response transformation. J Neurophysiol 40: 463–479
Hubel DH, Wiesel TO (1962) Receptive fields, binocular interaction and functional architecture in the cat's visual cortex. J Physiol (Lond) 160: 106–154
Hubel DH, Wiesel TN (1968) Receptive fields and functional architecture of monkey striate cortex. J Physiol (Lond) 195: 215–243
Hyvärinen J, Poranen A (1978a) Movement-sensitive and direction and orientation-selective cutaneous receptive fields in the hand area of the postcentral gyrus in monkeys. J Physiol (Lond) 283: 523–537
Hyvärinen J, Poranen A (1978b) Receptive field integration and submodality convergence in the hand area of the post-central gyrus of the alert monkey. J Physiol (Lond) 283: 539–556
Krieg WJS (1946) Connections of the cerebral cortex. I. The albino rat. B. Structure of the cortical areas J Comp Neurol 84: 277–323
Lamour Y, Willer JC, Guilbaud G (1983a) Rat somatosensory (SmI) cortex:I. Characteristics of neuronal responses to noxious stimulation and comparison with responses to nonnoxious stimulation Exp Brain Res 49: 35–45
Lamour Y, Guilbaud G, Wilier JC (1983b) Rat somatosensory (SmI) cortex: II. Laminar and columnar organization of noxious and non-noxious inputs Exp Brain Res 49: 46–54
Mountcastle VB Talbot WH, Sakata H, Hyvärinen J (1969) Cortical neuronal mechanisms in flutter-vibration studied in unanesthetized monkeys. Neuronal periodicity and frequency discrimination J Neurophysiol 32: 452–484
Mountcastle VB (1957) Modality and topographic properties of single neurons of cat's somatic sensory cortex. J Neurophysiol 20: 408–434
Mountcastle VB, Powell TPS (1959) Neural mechanisms subserving cutaneous sensibility, with special reference to the role of afferent inhibition in sensory perception and discrimination. Bull Johns Hopkins Hosp 105: 201–232
Sasaki H, Bear DM, Ervin FR (1971) Quantitative characterization of unit response in the visual system. Exp Brain Res 239–255
Schiller PH, Finlay BL, Volman SF (1976) Quantitative studies of single-cell properties in monkey striate cortex. I. Spatiotemporal organization of receptive fields. J Neurophysiol 39: 1288–1319
Simons DJ (1978) Response properties of vibrissa units in rat SI somatosensory neocortex. J Neurophysiol 41: 798–820
Towe AL, Kennedy XT (1961) Response of cortical neurons to variation of stimulus intensity and locus. Exp Neurol 3: 570–587
Uhr JL, Chapin JK, Woodward DJ (1981) Cortical and thalamic connections of rat barelfield cortex. Abstr Soc Neurosci Ann Meeting
Uhr JL, Chapin JK (1983) Contribution of thalamo-cortical and cortico-cortical connections to receptive field properties in rat SI cortex. Abstr Soc Neurosci Ann Meeting
Werner G, Whitsel B (1970) Stimulus feature detection by neurons in somatosensory areas I and II of primates. IEEE Trans Man-machine Syst 11: 36–38
Whitsel BL, Roppolo JR, Werner G (1972) Cortical information processing of stimulus motion on primate skin. J Neurophysiol 35: 691–717
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Chapin, J.K. Laminar differences in sizes, shapes, and response profiles of cutaneous receptive fields in the rat SI cortex. Exp Brain Res 62, 549–559 (1986). https://doi.org/10.1007/BF00236033
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00236033