Tachykinin receptors on motoneurons in the spinal cords of neonatal rats, gerbils and hamsters.
As a step to clarify the profiles of tachykinin receptors in the mammalian central nervous system, we examined the effects of various tachykinin receptor agonists and antagonists on motoneurons in isolated spinal cord preparations from rats, gerbils and hamsters. After treatment with tetrodotoxin, potential changes were recorded extracellularly from lumbar ventral roots at 27 degrees C. Bath-application of tachykinin NK1, NK3 receptor agonists produced depolarizing responses of ventral roots. In contrast, selective NK2 agonists exerted no or only marginal depolarizing action. Neurokinin A (NKA), however, exerted a distinct depolarizing action on motoneurons. Tachykinin NK1 receptor antagonists antagonized the actions of SPOMe and NKA in a competitive manner. The present results suggest that tachykinin NK1 and NK3 receptors are present on spinal motoneurons of newborn rats, gerbils and hamsters, and that NKA acts on the NK1 receptors.
Guo
J Z
JZ
Department of Pharmacology, Faculty of Medicine, Tokyo Medical and Dental University, Japan. phmjz@gwumc.edu
Yoshioka
K
K
Hosoki
R
R
Otsuka
M
M
D000818:Animals; D000831:Animals, Newborn; D006224:Cricetinae; D004558:Electric Stimulation; D005260:Female; D005849:Gerbillinae; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D009046:Motor Neurons / Q000187:drug effects / Q000502:physiology*; D010880:Piperidines / Q000494:pharmacology; D051381:Rats; D018039:Receptors, Tachykinin / Q000819:agonists / Q000037:antagonists & inhibitors / Q000502:physiology*; D013116:Spinal Cord / Q000187:drug effects / Q000502:physiology*; D013126:Spinal Nerve Roots / Q000187:drug effects; D013237:Stereoisomerism
D010880:Piperidines; D018039:Receptors, Tachykinin; C080755:3-(2-methoxybenzylamino)-2-phenylpiperidine