Skip to main content
NCBI home page
The Journal of Physiology logoLink to The Journal of Physiology
. 1989 Jun;413:107–118. doi: 10.1113/jphysiol.1989.sp017644

Spatial spread of in-field afferent inhibition in the cat's spinocervical tract.

R Noble 1, A D Short 1
PMCID: PMC1189091  PMID: 2557435

Abstract

1. Extracellular microelectrode recordings were made from twenty-three spinocervical tract (SCT) cells in the lumbar spinal cord of cats anaesthetized with chloralose and paralysed with gallamine triethiodide. Excitation and inhibition of the cells were elicited by applying small brief (4 mN, 60 ms) localized jets of air to the clipped hair in and around the receptive fields. 2. Receptive field extents ranged from 40 to 180 mm. Excitation occurred in the period 30-130 ms after the start of the stimulus, and in-field afferent inhibition from 130 ms up to 700 ms or more. The inhibition was manifest as a reduction in background discharge and as a reduction in responsiveness to a test stimulus which followed a conditioning stimulus. 3. When the conditioning stimulus was spatially separated from the test stimulus, the degrees of in-field afferent inhibition depended on the spatial separation, even when both were within the excitatory receptive field. The spatial spread of in-field afferent inhibition was limited to 100 mm or less. 4. In two units only, afferent inhibition was produced from a narrow strip just outside the excitatory receptive field. In the other units, it could only be produced from within the excitatory receptive field. 5. The results suggest that the inhibitory input to SCT cells is organized in subdomains no more than 100 mm across, which may correspond to the receptive fields of interneurones between the primary afferent fibres and the SCT cells.

Full text

PDF
107

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Brown A. G., Fyffe R. E., Noble R., Rose P. K., Snow P. J. The density, distribution and topographical organization of spinocervical tract neurones in the cat. J Physiol. 1980 Mar;300:409–428. doi: 10.1113/jphysiol.1980.sp013169. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Brown A. G., Koerber H. R., Noble R. Actions of trains and pairs of impulses from single primary afferent fibres on single spinocervical tract cells in cat. J Physiol. 1987 Jan;382:313–329. doi: 10.1113/jphysiol.1987.sp016369. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Brown A. G., Koerber H. R., Noble R. An intracellular study of spinocervical tract cell responses to natural stimuli and single hair afferent fibres in cats. J Physiol. 1987 Jan;382:331–354. doi: 10.1113/jphysiol.1987.sp016370. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Brown A. G., Koerber H. R., Noble R. Excitatory actions of single impulses in single hair follicle afferent fibres on spinocervical tract neurones in the cat. J Physiol. 1987 Jan;382:291–312. doi: 10.1113/jphysiol.1987.sp016368. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Brown A. G., Maxwell D. J., Short A. D. Receptive fields and in-field afferent inhibition of neurones in the cat's lateral cervical nucleus. J Physiol. 1989 Jun;413:119–137. doi: 10.1113/jphysiol.1989.sp017645. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Brown A. G., Noble R., Rowe M. J. Receptive field profiles and integrative properties of spinocervical tract cells in the cat. J Physiol. 1986 May;374:335–348. doi: 10.1113/jphysiol.1986.sp016082. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Gardner E. P., Costanzo R. M. Spatial integration of multiple-point stimuli in primary somatosensory cortical receptive fields of alert monkeys. J Neurophysiol. 1980 Feb;43(2):420–443. doi: 10.1152/jn.1980.43.2.420. [DOI] [PubMed] [Google Scholar]
  8. Hongo T., Jankowska E., Lundberg A. Post-synaptic excitation and inhibition from primary afferents in neurones of the spinocervical tract. J Physiol. 1968 Dec;199(3):569–592. doi: 10.1113/jphysiol.1968.sp008669. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Jänig W., Schoultz T., Spencer W. A. Temporal and spatial parameters of excitation and afferent inhibition in cuneothalamic relay neurons. J Neurophysiol. 1977 Jul;40(4):822–835. doi: 10.1152/jn.1977.40.4.822. [DOI] [PubMed] [Google Scholar]
  10. Jänig W., Spencer W. A., Younkin S. G. Spatial and temporal features of afferent inhibition of thalamocortical relay cells. J Neurophysiol. 1979 Sep;42(5):1450–1460. doi: 10.1152/jn.1979.42.5.1450. [DOI] [PubMed] [Google Scholar]
  11. Laskin S. E., Spencer W. A. Cutaneous masking. II. Geometry of excitatory andinhibitory receptive fields of single units in somatosensory cortex of the cat. J Neurophysiol. 1979 Jul;42(4):1061–1082. doi: 10.1152/jn.1979.42.4.1061. [DOI] [PubMed] [Google Scholar]

Articles from The Journal of Physiology are provided here courtesy of The Physiological Society

RESOURCES