Summary
The companion article (Sholomenko et al. 1991) described the brainstem locomotor regions in the bird where direct intracerebral injection of a number of putative excitatory neurochemicals, including cholinergic agonists, N-methyl-d-aspartate (NMDA) and Substance P, evoke locomotion. Using the same experimental protocol, this study focuses on the locomotor effects following discrete brainstem injections of the inhibitory neurotransmitter, γ-aminobutyric acid (GABA), and some of GABA agonists and antagonists. Brainstem regions that were electrically and chemically stimulated included the ventromedial medullary reticular formation, the pontobulbar locomotor strip of the dorsolateral pons and medulla, the pontine reticular formation, and the mesencephalic reticular formation. Locomotion was evoked after the injection of the GABA antagonists picrotoxin (a GABAA receptor antagonist) and bicuculline (GABAA antagonist) into several brainstem locomotor regions. Brainstem stimulated locomotion (both chemically and electrically induced) could be transiently blocked by intracerebral infusion of GABA and irreversibly blocked by muscimol (GABAA agonist). Our avian results are similar to those described for mammals and provide support for the suggestion that motor circuitry, at least at brainstem levels, is similar in all vertebrates.
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References
Awapara J, Landua AJ, Fuerst R, Seale B (1950) Free γ-aminobutyric acid in brain. J Biol Chem 187:35–39
Barnard EA, Darlison MG, Seeburg P (1987) Molecular biology of the GABAA receptor: the receptor/channel superfamily. TINS 10:502–508
Bloom FE (1985) Neurohumoral transmission and the central nervous system. In: Goodman Gilman A, Goodman LS, Rall TW, Murad (eds) The pharmacological basis of therapeutics. Macmillan, New York, pp 236–259
Brudzynski SM, Mogenson GJ (1986) Decrease in locomotor activity by injections of carbachol in the anterior hypothalamic preoptic area of the rat. Brain Res 376:38–46
Brudzynski SM, Wu M, Mogenson GJ (1988) Modulation of locomotor activity induced by injections of carbachol into the tegmental pedunculopontine nucleus and adjacent areas in the rat. Brain Res 451:119–125
Dietl MM, Cortes R, Palacios JM (1988) Neurotransmitter receptors in the avian brain. III. GABA-benzodiazepine receptors. Brain Res 439:366–371
Eldridge FL, Millhorn DE, Kiley JP, Waldrop TG (1985) Stimulation by central command of locomotion, respiration and circulation during exercise. Respir Physiol 59:313–337
Franz DN (1985) Central nervous system stimulants. In: Goodman Gilman A, Goodman LS, Rall TW, Murad F (eds), The pharmacological basis of therapeutics. MacMillan, New York, 7th ed, pp 582–588
Garcia-Rill E, Skinner RD (1986) The basal ganglia and the mesencephalic locomotor region. In: Grillner S, Herman RM, Stein PSG, Forssberg H, Stuart DG (eds) Neural control of vertebrate locomotion. MacMillan Press, London, pp 77–103
Garcia-Rill E, Skinner RD (1987) The mesencephalic locomotor region. I. Activation of the medullary projection site. Brain Res 411:1–12
Garcia-Rill E, Skinner RD, Fitzgerald FA (1985) Chemical activation of the mesencephalic locomotor region (MLR). Brain Res 330:43–54
Garcia-Rill E, Skinner RD, Conrad C, Mosley D, Campbell C (1986) Projections of the mesencephalic locomotor region in the rat. Brain Res Bull 17:33–40
Garcia-Rill E, Skinner RD, Gilmore SA, Owings R (1983b) Connections of the mesencephalic locomotor region (MLR) IL afferents and efferents. Brain Res Bull 10:63–71
Garcia-Rill E, Skinner RD, Jackson MB, Smith MM (1983a) Connections of the mesencephalic locomotor region (MLR) I. substantia nigra afferents. Brain Res Bull Vol 10:57–62
Kazennikov OV, Shik ML, Yakovleva GV (1983) Responses of upper cervical spinal neurons in cats to stimulation of the brainstem locomotor region at different frequencies. Neurophysiology 15:256–261
Kerr DI, Ong J, Prager RH, Gynther BD, Curtis DR (1987) Phaclofen; a peripheral and central baclofen antagonist. Brain Res 405:150–154
Krogsgaard-Larsen P, Falch E, Peet MJ, Leah JD, Curtis DR (1983) Molecular pharmacology of the GABA receptors and GABA agonists. In: Mandel P, DeFeudis FV (ed) Advances in Biochemical Psychopharmacology Vol 37, CNS Receptors From Molecular Pharmacology to Behavior. Raven Press, New York, pp 1–13
Mogenson GJ, Swanson LW, Wu M (1985) Evidence that projections from substantia innominata to zona incerta and mesencephalic locomotor region contribute to locomotor activity. Brain Res 334:65–76
Mogenson GJ, Wu M (1986) Subpallidal projections to the mesencephalic locomotor region investigated with a combination of behavioral and electrophysiological recording techniques. Brain Res Bull 16:383–390
Mugnaini E, Oertel WH (1985) An atlas of the distribution of GABAergic neurons and terminal in the rat CNS as revealed by GAD immunohistochemistry. In: Björklund A, Hökfelt T (eds) Handbook of chemical neuroanatomy, Vol 4. GABA and Neuropeptides in the CNS, Part I. Elsevier, Amsterdam, pp 436–662
Noga BR, Kettler J, Jordan LM (1988) Locomotion produced in mesencephalic cats by injection of putative transmitter substances and antagonists into the medial reticular formation and the pontomedullary locomotor strip. J Neurosci 8:2074–2086
Olsen RW (1981) GABA-benzodiazepine-barbiturate receptor interactions. J Neurochem 37:1–13
Roberts E, Frankel S (1950) γ-Aminobutyric acid in brain: its formation from glutamic acid. J Biol Chem 187:55–63
Selionov VA, Shik ML (1984) Medullary locomotor strip and column in the cat. Neurosci 13:1267–1278
Shefchyck SJ, Jell RM, Jordan LM (1984) Reversiblecooling of the brainstem reveals areas required for mesencephalic locomotor region evoked treadmill locomotion. Exp Brain Res 56:257–262
Shik ML, Yagodnitsyn AS (1977) The pontobulbar “locomotor strip”. Neurophysiology 9:95–97
Sholomenko GN, Funk GD, Steeves JD (1991) Avian locomotion activated by intracerebral infusion of neurotransmitter agonists and antagonists. I. Acetylcholine, excitatory amino acids and substance P. Exp Brain Res 85:659–673
Steeves JD, Sholomenko GN, Webster DMS (1987) Stimulation of the pontomedullary reticular formation initiates locomotion in decerebrate birds. Brain Res 401:205–212
Webster DMS, Steeves JD (1988) Origins of brainslem-spinal projections in the duck and goose. J Comp Neurol 273:573–583
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Sholomenko, G.N., Funk, G.D. & Steeves, J.D. Avian locomotion activated by brainstem infusion of neurotransmitter agonists and antagonists. Exp Brain Res 85, 674–681 (1991). https://doi.org/10.1007/BF00231753
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DOI: https://doi.org/10.1007/BF00231753