Summary
Microelectrode recordings were made from ascending fibres of the spinocervical tract in spinal, decerebrate and anaesthetized cats. Three types of unit were recognised in spinal cats on the basis of their response to mechanical stimulation; units excited by 1. hair movement; 2. hair movement and skin pressure; 3. pressure and pinch of the skin. Five types were recognised in decerebrate and anaesthetized cats; units excited by 1. movement of guard hairs and skin pressure; 2. movement of tylotrich hairs; 3. movement of all the hairs and skin pressure; 4. pressure and pinch of the skin; 5. units which could not be influenced from the periphery. The presence or absence of inhibitory fields and the mean rate of spontaneous discharges depended on the type of preparation and the type of unit. The differences between spinal and decerebrate or anaesthetized cats suggest that a descending neuronal system, intact in the decerebrate and anaesthetized animals, operates to control the input to the spinocervical tract.
The mean frequency of response of units sensitive to hair movement was related to the velocity of hair movement by a power function. All units responded with an increased frequency of discharge to heating the skin to high temperatures, the degree of response depending on the preparation and type of unit. Some units responded with an increased discharge to low skin temperatures.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Andersson, S.A.: Projection of different spinal pathways to the second somatosensory area in the cat. Acta physiol. scand. 56, Suppl. 194 (1962).
Armett, C.J., and R.W. Hunsperger: Excitation of receptors in the pad of the cat by single and double mechanical pulses. J. Physiol. (Lond.) 158, 15–38 (1961).
Brodal, A., and B. Rexed: Spinal afferents to the lateral cervical nucleus in the cat. An experimental study. J. comp. Neurol. 98, 179–213 (1933).
Brown, A.G.: Cutaneous afferent fibre collaterals in the dorsal columns of the cat. Exp. Brain Res. 5, 293–305 (1968a).
— Single unit activity in the spinocervical tract of the cat. J. Physiol. (Lond.) 198, 62–63P. (1968b).
Brown, A.G., and A. Iggo: A quantitative study of cutaneous receptors and afferent fibres in the cat and rabbit. J. Physiol. (Lond.) 193, 707–733 (1967).
Burgess, P.R.: A study of the transmission of sensory information in the cat spinal cord. Ph. D. Thesis. Rockefeller Institute, N.Y. (1965).
—, and E.R. Perl: Myelinated afferent fibres responding specifically to noxious stimulation of the skin. J. Physiol. (Lond.) 190, 541–562 (1967).
Chambers Margaret R., and A. Iggo: Slowly-adapting cutaneous mechanoreceptors. J. Physiol. (Lond.) 192, 28–27 P. (1967).
Eccles, J.C., R.M. Eccles and A. Lundberg: Types of neurons in and around the intermediate nucleus of the lumbosacral cord. J. Physiol. (Lond.) 154, 89–114 (1960).
Fuller, D.R.G., and J.A.B. Gray: The relation between mechanical displacements applied to a cat's pad and the resultant impulse patterns. J. Physiol. (Lond.) 182, 465–483 (1966).
Gordon, G., and M.G.M. Jukes: Dual organization of the exteroceptive components of the cat's gracile nucleus. J. Physiol. (Lond.) 173, 263–290 (1964).
Hensel, H., A. Iggo and Ingrid Witt: A quantitative study of sensitive cutaneous thermoreceptors with C afferent fibres. J. Physiol. (Lond.) 153, 113–126 (1960).
Hubel, D.H.: Tungsten microelectrodes for recording from single units. Science 125, 549–550 (1957).
Iggo, A.: Cutaneous heat and cold receptors with slowly-conducting (C) afferent fibres. Quart. J. exp. Physiol. 44, 362–370 (1959).
—: Cutaneous mechanoreceptors with afferent C fibres. J. Physiol. (Lond.) 152, 337–353 (1960).
—: New specific sensory structures in hairy skin. Acta neuroveg. (Wien) 24, 175–180 (1963).
Iriuchjima, J., and Y. Zotterman: The specificity of afferent cutaneous C fibres in mammals. Acta physiol. scand. 49, 267–278 (1960).
Landgren, S., A. Nordwall and O. Wengström: The location of the thalamic relay in the spino-cervical-lemniscal pathway. Acta physiol. scand. 65, 164–175 (1965).
Lundberg, A.: Ascending spinal hindlimb pathways in the cat. In: Progress in Brain Research, vol. 12, pp. 135–163. Ed. by J.C. Eccles and J.P. Schadé. Amsterdam-London-New York: Elsevier 1964.
—, and O. Oscarsson: Three ascending spinal pathways in the dorsal part of the lateral funiculus. Acta physiol. scand. 51, 1–16 (1961).
Mark, R.F., and J. Steiner: Cortical projection of impulses in myelinated cutaneous afferent nerve fibres of the cat. J. Physiol. (Lond.) 142, 544–562 (1958).
Mendell, L.M.: Physiological properties of unmyelinated fiber projection to the spinal cord. Exp. Neurol. 16, 316–332 (1966).
Morin, F.: Anew spinal pathway for cutaneous impulses. Amer. J. Physiol. 183, 245–252 (1955).
—, and J.V. Catalano: Central connections of a cervical nucleus (nucleus cervicalis lateralis of the cat). J. comp. Neurol. 103, 17–32 (1955).
Norrsell, U., and P. Voorhoeve: Tactile pathways from the hindlimb to the cerebral cortex in cat. Acta physiol. scand. 54, 9–17 (1962).
—, and E.R. Wolpow: An evoked potential study of different pathways from the hindlimb to the somatosensory areas in the cat. Acta physiol. scand. 66, 19–33 (1966)
Oswaldo-Cruz, E., and C. Kidd: Functional properties of neurones in the lateral cervical nucleus of the cat. J. Neurophysiol. 27, 1–14 (1964).
Rexed, B., and G. Ström: Afferent nervous connections of the lateral cervical nucleus. Acta physiol. scand. 25, 219–229 (1952).
Stevens, S.S.: On the psychophysical law. Psychol. Rev. 64, 153–181 (1957).
Taub, A.: Local, segmental and supraspinal interaction with a dorsolateral spinal cutaneous afferent system. Exp. Neurol. 10, 357–374 (1964).
—, and P.O. Bishop: The spinocervical tract: Dorsal column linkage, conduction velocity, primary afferent spectrum. Exp. Neurol. 13, 1–21 (1965).
Wall, P.D.: Cord cells responding to touch, damage and temperature of skin. J. Neurophysiol. 23, 197–210 (1960).
—: The laminar organization of dorsal horn and effects of descending impulses. J. Physiol. (Lond.) 188, 403–424 (1967).
Author information
Authors and Affiliations
Additional information
Part of the apparatus used was supplied by a Royal Society Grant-in-aid of Scientific Investigations to A.G.B.
Supported by a U.S.P.H.S. Postdoctoral Fellowship (F2 NB 34, 495) from the National Institute of Neurological Diseases and Blindness. Present address: Department of Pharmacology, College of Medicine, University of Utah, Salt Lake City, Utah, USA.
Rights and permissions
About this article
Cite this article
Brown, A.G., Franz, D.N. Responses of spinocervical tract neurones to natural stimulation of identified cutaneous receptors. Exp Brain Res 7, 231–249 (1969). https://doi.org/10.1007/BF00239031
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00239031