Skip to main content
PMC home page
The Journal of Physiology logoLink to The Journal of Physiology
. 1972 Nov;226(3):825–846. doi: 10.1113/jphysiol.1972.sp010012

Factors forming the edge of a receptive field: the presence of relatively ineffective afferent terminals

E G Merrill, P D Wall
PMCID: PMC1331179  PMID: 4637631

Abstract

A specialized type of spinal cord cell has its cell body in lamina IV and has a small low threshold cutaneous receptive field which is remarkable for its abrupt edge. No signs could be found of a subliminal fringe to this field since its size remains fixed during wide excursions of the cell's excitability. Reversible blocking of peripheral nerves and dorsal roots showed that the afferents responsible for exciting these cells following natural stimuli, run in a restricted area of peripheral nerve and dorsal root. When the fibres necessary to sustain the natural stimulus receptive field were blocked, it was shown that other large myelinated fibres in neighbouring roots were still capable of firing the cell monosynaptically following electrical stimulation of the root or periphery although no natural stimuli were able to change the cell's excitability. It is necessary to divide the afferent synapses on such cells into a class which is highly effective in firing the cell on natural stimulation and a second class which has no effect yet detected following natural stimuli but which can fire the cell monosynaptically if synchronously activated by electrical stimulation. Suggestions are made for possible presynaptic and post-synaptic mechanisms which might divide the effect of arriving impulses into two such classes.

Full text

PDF
825

Selected References

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

  1. Barron D. H., Matthews B. H. Intermittent conduction in the spinal cord. J Physiol. 1935 Aug 22;85(1):73–103. doi: 10.1113/jphysiol.1935.sp003303. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Brown A. G. Effects of descending impulses on transmission through the spinocervical tract. J Physiol. 1971 Dec;219(1):103–125. doi: 10.1113/jphysiol.1971.sp009652. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Chung S. H., Raymond S. A., Lettvin J. Y. Multiple meaning in single visual units. Brain Behav Evol. 1970;3(1):72–101. doi: 10.1159/000125464. [DOI] [PubMed] [Google Scholar]
  4. DARIAN-SMITH I., PROCTOR R., RYAN R. D. A SINGLE-NEURONE INVESTIGATION OF SOMATOTOPIC ORGANIZATION WITHIN THE CAT'S TRIGEMINAL BRAIN-STEM NUCLEI. J Physiol. 1963 Aug;168:147–157. doi: 10.1113/jphysiol.1963.sp007183. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Fetz E. E. Pyramidal tract effects on interneurons in the cat lumbar dorsal horn. J Neurophysiol. 1968 Jan;31(1):69–80. doi: 10.1152/jn.1968.31.1.69. [DOI] [PubMed] [Google Scholar]
  6. Gobel S., Dubner R. Fine structural studies of the main sensory trigeminal nucleus in the cat and rat. J Comp Neurol. 1969 Dec;137(4):459–493. doi: 10.1002/cne.901370405. [DOI] [PubMed] [Google Scholar]
  7. HOWLAND B., LETTVIN J. Y., McCULLOCH W. S., PITTS W., WALL P. D. Reflex inhibition by dorsal root interaction. J Neurophysiol. 1955 Jan;18(1):1–17. doi: 10.1152/jn.1955.18.1.1. [DOI] [PubMed] [Google Scholar]
  8. Hillman P., Wall P. D. Inhibitory and excitatory factors influencing the receptive fields of lamina 5 spinal cord cells. Exp Brain Res. 1969;9(4):284–306. doi: 10.1007/BF00235240. [DOI] [PubMed] [Google Scholar]
  9. 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]
  10. KATZ B., MILEDI R. A STUDY OF SPONTANEOUS MINIATURE POTENTIALS IN SPINAL MOTONEURONES. J Physiol. 1963 Sep;168:389–422. doi: 10.1113/jphysiol.1963.sp007199. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. KRNJEVIC K., MILEDI R. Presynaptic failure of neuromuscular propagation in rats. J Physiol. 1959 Dec;149:1–22. doi: 10.1113/jphysiol.1959.sp006321. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. KUNO M. QUANTAL COMPONENTS OF EXCITATORY SYNAPTIC POTENTIALS IN SPINAL MOTONEURONES. J Physiol. 1964 Dec;175:81–99. doi: 10.1113/jphysiol.1964.sp007504. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Katz B. A note on interaction between nerve fibres. J Physiol. 1942 Mar 31;100(4):369–371. doi: 10.1113/jphysiol.1942.sp003948. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Kerr F. W. The fine structure of the subnucleus caudalis of the trigeminal nerve. Brain Res. 1970 Oct 13;23(2):129–145. doi: 10.1016/0006-8993(70)90035-1. [DOI] [PubMed] [Google Scholar]
  15. MENDELL L. M., WALL P. D. PRESYNAPTIC HYPERPOLARIZATION: A ROLE FOR FINE AFFERENT FIBRES. J Physiol. 1964 Aug;172:274–294. doi: 10.1113/jphysiol.1964.sp007417. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Mark R. F., Marotte L. R., Johnstone J. R. Reinnervated eye muscles do not respond to impulses in foreign nerves. Science. 1970 Oct 9;170(3954):193–194. doi: 10.1126/science.170.3954.193. [DOI] [PubMed] [Google Scholar]
  17. Pomeranz B., Wall P. D., Weber W. V. Cord cells responding to fine myelinated afferents from viscera, muscle and skin. J Physiol. 1968 Dec;199(3):511–532. doi: 10.1113/jphysiol.1968.sp008666. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. RALL W. Theory of physiological properties of dendrites. Ann N Y Acad Sci. 1962 Mar 2;96:1071–1092. doi: 10.1111/j.1749-6632.1962.tb54120.x. [DOI] [PubMed] [Google Scholar]
  19. SZENTAGOTHAI J. NEURONAL AND SYNAPTIC ARRANGEMENT IN THE SUBSTANTIA GELATINOSA ROLANDI. J Comp Neurol. 1964 Apr;122:219–239. doi: 10.1002/cne.901220207. [DOI] [PubMed] [Google Scholar]
  20. Scheibel M. E., Scheibel A. B. Terminal axonal patterns in cat spinal cord. II. The dorsal horn. Brain Res. 1968 Jun;9(1):32–58. doi: 10.1016/0006-8993(68)90256-4. [DOI] [PubMed] [Google Scholar]
  21. TAUB A. LOCAL, SEGMENTAL AND SUPRASPINAL INTERACTION WITH A DORSOLATERAL SPINAL CUTANEOUS AFFERENT SYSTEM. Exp Neurol. 1964 Oct;10:357–374. doi: 10.1016/0014-4886(64)90006-8. [DOI] [PubMed] [Google Scholar]
  22. WALL P. D. Cord cells responding to touch, damage, and temperature of skin. J Neurophysiol. 1960 Mar;23:197–210. doi: 10.1152/jn.1960.23.2.197. [DOI] [PubMed] [Google Scholar]
  23. WALL P. D., TAUB A. Four aspects of trigeminal nucleus and a paradox. J Neurophysiol. 1962 Jan;25:110–126. doi: 10.1152/jn.1962.25.1.110. [DOI] [PubMed] [Google Scholar]
  24. Wall P. D., Egger M. D. Formation of new connexions in adult rat brains after partial deafferentation. Nature. 1971 Aug 20;232(5312):542–545. doi: 10.1038/232542a0. [DOI] [PubMed] [Google Scholar]
  25. Wall P. D. Impulses originating in the region of dendrites. J Physiol. 1965 Sep;180(1):116–133. [PMC free article] [PubMed] [Google Scholar]
  26. Wall P. D. The laminar organization of dorsal horn and effects of descending impulses. J Physiol. 1967 Feb;188(3):403–423. doi: 10.1113/jphysiol.1967.sp008146. [DOI] [PMC free article] [PubMed] [Google Scholar]

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

RESOURCES