Summary
In ten cats, single unit electrical activity was recorded in the lumbosacral spinal cord from neurones driven by stimulation of afferent fibres from the ipsilateral knee joint. Tonic descending inhibition (TDI) on the responses of these cells was measured as increases in resting and evoked activity of the neurones following reversible spinalization of the animals with a cold block at upper lumbar level. Acute inflammation of the knee joint was induced in five of the cats by the injection of kaolin and carrageenan into the joint. TDI was observed in 25 of 33 neurones recorded in normal animals (76%) and in 36 of 40 (90%) neurones recorded in animals with acute knee joint inflammation. In both kinds of preparation TDI was more pronounced in neurones recorded in the deep dorsal horn and in the ventral horn than in those recorded in the superficial dorsal horn. There was a tendency in the whole sample for TDI to be greater in neurones with input from inflamed knees. We conclude that the spinal processing of afferent information from joints is under tonic descending influences and that the amount of TDI can be altered during acute arthritis.
Similar content being viewed by others
References
Besson J-M, Chaouch A (1987) Peripheral and spinal mechanisms of nociception. Physiol Rev 67:67–186
Cervero F, Iggo A, Ogawa H (1976) Nociceptor-driven dorsal horn neurones in the lumbar spinal cord of the cat. Pain 1:5–24
Cervero F, Iggo A, Molony V (1977) Responses of spinocervical tract neurones to noxious stimulation of the skin. J Physiol 267:537–558
Cervero F, Plenderleith MB (1985) C-fibre excitation and tonic descending inhibition of dorsal horn neurones in adult rats treated at birth with capsaicin. J Physiol 365:223–237
Cervero F, Neugebauer V, Schaible H-G, Schmidt RF (1990) Changes in tonic descending inhibition of spinal cord neurones induced by acute inflammation of the knee joint in anaesthetized cats. J Physiol 420:39P
Duggan AW (1982) Brain stem control of the responses of spinal neurones to peripheral stimuli. TINS 5:127–130
Duggan AW (1985) Pharmacology of descending control systems. Philos Trans R Soc Series B 308:375–391
Gebhart GF (1986) Modulatory effects of descending systems on spinal dorsal horn neurons. In: TL Yaksh (ed) Spinal afferent processing. Plenum Press, New York, pp 391–416
Holtz A, Nystrom B, Gerdin B (1988) Regulation of spinal cord blood flow in the rat as measured by quantitative autoradiography. Acta Physiol Scand 133:455–493
Hong SK, Kniffki KD, Mense S, Schmidt RF, Wendisch M (1979) Descending influences on the responses of spinocervical tract neurones to chemical stimulation of fine muscle afferents. J Physiol 290:129–140
Laird JMA, Cervero F (1989) A comparative study of the changes in receptive field properties of multireceptive and nocireceptive rat dorsal horn neurons following noxious mechanical stimuli. J Neurophysiol 62:854–863
Laird JMA, Cervero F (1990) Tonic descending influences on the receptive field properties of nociceptive neurons in the sacral spinal cord of the rat. J Neurophysiol 63:1022–1032
Schaible H-G, Schmidt RF (1983) Activation of groups III and IV sensory units in medial articular nerve by local mechanical stimulation of the knee joint. J Neurophysiol 49:35–44
Schaible H-G, Schmidt RF (1985) Effects of an experimental arthritis on the sensory properties of fine articular afferent units. J Neurophysiol 54:1109–1122
Schaible H-G, Schmidt RF, Willis WD (1987) Enhancement of the responses of ascending tract cells in the cat spinal cord by acute inflammation of the knee joint. Exp Brain Res 66:489–499
Schaible H-G, Neugebauer V, Cervero F, Schmidt RF (1989) Descending inhibition on spinal neurons with input from normal and acutely inflammed knees in the cat. Soc Neurosci Abstr 15:181
Tattersall JH, Cervero F, Lumb BM (1886) Effects of reversible spinalization on the visceral input to viscero-somatic neurons in the lower thoracic spinal cord of the cat. J Neurophysiol 56:785–796
Willis WD (1982) Control of nociceptive transmission in the spinal cord. Progr Sens Physiol 3:1–159
Author information
Authors and Affiliations
Additional information
Department of Physiology, University of Bristol Medical School, University Walk, Bristol BS8 1TD, U.K.
Rights and permissions
About this article
Cite this article
Cervero, F., Schaible, H.G. & Schmidt, R.F. Tonic descending inhibition of spinal cord neurones driven by joint afferents in normal cats and in cats with an inflamed knee joint. Exp Brain Res 83, 675–678 (1991). https://doi.org/10.1007/BF00229846
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00229846