Advertisement

Experimental Brain Research

, Volume 76, Issue 1, pp 27–37 | Cite as

Comparison of effects of monoamines on transmission in spinal pathways from group I and II muscle afferents in the cat

  • H. Bras
  • P. Cavallari
  • E. Jankowska
  • D. McCrea
Article

Summary

The actions of noradrenaline (NA) and 5-hydroxytryptamine (5-HT; serotonin) were compared with those of L-3,4-dihydroxyphenylalanine methyl ester (Methyl-L-DOPA) on transmission to spinal interneurones in mid-lumbar (L4 and L5) segments of the cat spinal cord. The drugs were applied ionophoretically and their effects were tested on monosynaptic field potentials evoked by nerve impulses in hindlimb group I and group II muscle afferent fibres and on responses of interneurones with synaptic input from these fibres. Of field potentials recorded at various locations, both NA and 5-HT depressed those evoked from group II fibres in the intermediate and ventral horn regions of the spinal cord but not, or only occasionally, in the dorsal horn. Field potentials of group I origin were not depressed. The tested interneurones were located where group II field potentials were affected. NA, 5-HT and Methyl-L-DOPA depressed responses to electrical stimulation of group II fibres but not responses evoked by group I fibres. The depression consisted of an increase in the latency and a decrease in the number of action potentials evoked by the stimuli. All three drugs were also found to decrease the amplitude of intracellularly recorded monosynaptic EPSPs of group II origin but not of monosynaptic EPSPs evoked in the same neurones by group I fibres. Interneuronal firing induced by DL-homocysteic acid was depressed as effectively as responses to electrical stimulation of peripheral nerves. The possibility of presynaptic and/or postsynaptic mechanisms of the selective depression of synaptic actions of group II origin are discussed.

Key words

Spinal interneurones Spinal reflexes Monoamines 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Andén NE, Jukes MGM, Lundberg A (1964) Spinal reflexes and monoamine liberation. Nature 202: 1222–1223Google Scholar
  2. Andén NE, Jukes MGM, Lundberg A, Vyklicky L (1966a) The effect of DOPA on the spinal cord. 1. Influence on transmission from primary afferents. Acta Physiol Scand 67: 373–386Google Scholar
  3. Andén NE, Jukes MGM, Lundberg A (1966b) The effect of DOPA on the spinal cord. 2. A pharmacological analysis. Acta Physiol Scand 67: 387–397Google Scholar
  4. Andersson G, Sjölund B (1978) The ventral spino-olivocerebellar system in the cat. IV. Spinal transmission after administration of clonidine and L-DOPA. Exp Brain Res 33: 227–240Google Scholar
  5. Baker RG, Andersson EG (1970) The effects of L-3,4-dihydroxyphenylalanine on spinal reflex activity. J Pharmac Exp Ther 173: 212–223Google Scholar
  6. Bannatyne BA, Maxwell DJ, Brown AG (1987) Fine structure of synapses associated with characterized postsynaptic dorsal column neurons in the cat. Neuroscience 23: 597–612Google Scholar
  7. Belcher G, Ryall RW, Schaffner R (1978) The differential effects of 5-hydroxytryptamine, noradrenaline and raphe stimulation on nociceptive and non-nociceptive dorsal horn neurones in the cat. Brain Res 151: 307–321Google Scholar
  8. Bergmans J, Miller S, Reitsma DJ (1973) Influence of L-DOPA on transmission in long ascending propriospinal pathways in the cat. Brain Res 62: 155–167Google Scholar
  9. Biscoe TJ, Curtis DR, Ryall RW (1966) An investigation of catecholamine receptors of spinal interneurons. Int J Neuropharmacol 5: 429–434Google Scholar
  10. Bras H, Cavallari P, Jankowska E (1988a) An investigation of local actions of ionophoretically applied DOPA in the spinal cord. Exp Brain Res 71: 447–449Google Scholar
  11. Bras H, Cavallari P, Jankowska E, McCrea D (1988b) Selective control of synaptic transmission, from one of two groups of afferents co-exciting the same neurones, by monoamines. Acta Physiol Scand 132: C8Google Scholar
  12. Butcher LL, Engel J, Fuxe K (1972) Behavioural, biochemical, and histochemical analyses of the central effects of monoamine precursors after peripheral decarboxylase inhibition. Brain Res 41: 387–411Google Scholar
  13. Carstens E, Klumpp D, Randic M, Zimmerman M (1981) Effect of iontophoretically applied 5-hydroxytryptamine on the excitability of single primary afferent C- and A-fibres in the cat spinal cord. Brain Res 220: 151–158Google Scholar
  14. Cavallari P, Edgley SA, Jankowska E (1987) Post-synaptic actions of midlumbar interneurones on motoneurones of hind-limb muscles in the cat. J Physiol (Lond) 389: 675–689Google Scholar
  15. Commissiong JW, Sedgwick EM (1979) Depletion of 5-HT by L-DOPA in spinal cord and brainstem of rat. Life Sci 25: 83–86Google Scholar
  16. Curds DR, Phillis JW, Watkins JC (1961) Cholinergic and non-cholinergic transmission in the mammalian spinal cord. J Physiol (Lond) 158: 296–323Google Scholar
  17. Davies J, Johnston SE (1984) Selective antinociceptive effects of tizanidine (DS 103-282), a centrally acting muscle relaxant, on dorsal horn neurones in the feline spinal cord. Br J Pharmacol 82: 409–421Google Scholar
  18. Dunlap K, Fischbach GI (1981) Neurotransmitters decrease the calcium conductance activated by depolarization of embryonic chick sensory neurones. J Physiol (Lond) 317: 519–535Google Scholar
  19. Eccles RM, Lundberg A (1959) Synaptic actions in motoneurones by afferents which may evoke the flexion reflex. Archs Ital Biol 97: 199–221Google Scholar
  20. Edgley SA, Jankowska E (1987a) Field potentials generated by group I and II muscle afferents in the middle lumbar segments of the cat spinal cord. J Physiol (Lond) 385: 393–413Google Scholar
  21. Edgley SA, Jankowska E (1987b) An interneuronal relay for group I and II muscle afferents in the midlumbar segments of the cat spinal cord. J Physiol (Lond) 389: 647–674Google Scholar
  22. Edgley SA, Jankowska E, Shefchyk S (1988) Evidence that midlumbar neurones in reflex pathways from group II afferents are involved in locomotion in the cat. J Physiol (Lond) 403: 57–73Google Scholar
  23. Engberg I, Ryall RW (1966) The inhibitory action of noradrenaline and other monoamines on spinal neurones. J Physiol (Lond) 185: 298–322Google Scholar
  24. Engberg I, Källström Y, Marshall KC (1972) Double micro manipulator for independent impalements of one neurone with two electrodes. Acta Physiol Scand 84: 4–5AGoogle Scholar
  25. Engberg I, Lundberg A, Ryall RW (1968) The effect of reserpine on transmission in the spinal cord. Acta Physiol Scand 72: 115–122Google Scholar
  26. Fu TC, Schomburg ED (1974) Electrophysiological investigation of the projection of secondary muscle spindle afferents in the cat spinal cord. Acta Physiol Scand 91: 314–329Google Scholar
  27. Headley PM, Duggan AW, Griersmith BT (1978) Selective reduction by noradrenaline and 5-hydroxytryptamine of nociceptive responses of cat dorsal horn neurones. Brain Res 145: 185–189CrossRefPubMedGoogle Scholar
  28. Hodge CJ, Woods CI, Delatizky J (1979) The efffects of L-DOPA on dorsal horn cell responses to innocuous skin stimulation. Brain Res 173: 271–285Google Scholar
  29. Horn J, McAfee D (1980) Alpha-adrenergic inhibition of calcium dependent potentials in rat sympathetic neurones. J Physiol 301: 191–204Google Scholar
  30. Howe JR, Zieglgänsberger W (1987) Responses of rat dorsal horn neurons to natural stimulation and to iontophoretically applied norepinephrine. J Comp Neurol 255: 1–17Google Scholar
  31. Jankowska J, Jukes MGM, Lund S, Lundberg A (1967) The effect of DOPA on the spinal cord. 5. Reciprocal organization of pathways transmitting excitatory action to alpha motoneurones of flexors and extensors. Acta Physiol Scand 70: 369–388Google Scholar
  32. Jordan LM, McCrea DA (1976) Analysis of effects of p-methoxyphenylethylamine on spinal cord neurones. Br J Pharmacol 57: 191–199Google Scholar
  33. Jordan LM, McCrea DA, Steeves JD, Menzies JE (1977) Noradrenergic synapses and effects of noradrenaline on interneurons in the ventral horn of the cat spinal cord. Can J Physiol Pharmacol 55: 399–412Google Scholar
  34. Lundberg A, Malmgren K, Schomburg ED (1987b) Reflex pathways from group II muscle afferents. 2. Functional characteristics of reflex pathways to alpha-motoneurones. Exp Brain Res 65: 282–293Google Scholar
  35. Marshall KC (1983) Catecholamines and their actions in the spinal cord. In: Davidoff RA (ed) Handbook of the spinal cord. M Decker, New York Basel, pp 275–328Google Scholar
  36. Marshall KC, Engberg I (1980) The effects of hydrogen ion on spinal neurons. J Can Physiol Pharmacol 58: 650–655Google Scholar
  37. Maxwell DJ, Fyffe REW, Brown AG (1984) Fine structure of normal and degenerating primary afferent boutons associated with characterized spinocervical tract neurons in the cat. Neuroscience 12: 151–163Google Scholar
  38. Phillis JW, Kirkpatrick JR (1979) Action of biogenic amines on the isolated toad spinal cord. J Gen Pharmacol 10: 115–119Google Scholar
  39. Schomburg ED, Steffens H (1988) The effect of DOPA and clonidine on reflex pathways from group II muscle afferents to alpha-motoneurones in the cat. Exp Brain Res 71: 442–446Google Scholar
  40. Shapiro E, Castelucci VF, Kandel ER (1980) Presynaptic inhibition in Aplysia involves a decrease in the Ca++ current of the presynaptic neuron. Proc Nat Acad Sci USA 77: 1185–1189Google Scholar
  41. Weight FF, Salmoiraghi GC (1966) Responses of spinal cord interneurons to acetylcholine, norepinephrine and serotonin administered by microelectrophoresis. J Pharmacol Exp Ther 153: 420–427Google Scholar
  42. Willis WD (1984) The raphe-spinal system. In: Brainstem control of spinal function. Academic Press, London New York, pp 141–214Google Scholar
  43. Wohlberg CJ, Hackman JC, Davidoff RA (1987) Epinephrine and norepinephrine modulate neuronal responses to excitatory amino acids and agonists in frog spinal cord. Synapse 1: 202–207Google Scholar
  44. Wohlberg CJ, Hackman JC, Ryan GP, Davidoff RA (1985) Epinephrine- and norepinephrine-evoked potential changes of frog primary afferent terminals: pharmacological characterization of α and β components. Brain Res 327: 289–301Google Scholar

Copyright information

© Springer-Verlag 1989

Authors and Affiliations

  • H. Bras
    • 1
  • P. Cavallari
    • 1
  • E. Jankowska
    • 1
  • D. McCrea
    • 1
  1. 1.Department of PhysiologyUniversity of GöteborgGöteborgSweden

Personalised recommendations