Substance P excites globus pallidus neurons in vivo.
Substance P is a member of the neurokinin family. Previous studies have reported the existence of substance P and its high-affinity receptor, neurokinin-1 receptor, in globus pallidus. Employing in vivo extracellular recording combined with behavioural tests, the effects of substance P in globus pallidus of rats were studied. Micropressure ejection of the selective neurokinin-1 receptor agonist [Sar9,Met(O2)11] substance P increased the spontaneous firing rate of pallidal neurons in a concentration-dependent manner, with increases of 27.3% at 0.01, 33.4% at 0.03, 45.5% at 0.1, 38.4% at 0.3 and 36.4% at 1.0 mm. The selective neurokinin-1 receptor antagonist SR140333B prevented the excitatory effects induced by [Sar9,Met(O2)11] substance P. In behaving rats, we observed the postural effects of neurokinin-1 receptor activation in the globus pallidus. Consistent with electrophysiological results, unilateral microinjection of [Sar9,Met(O2)11] substance P (0.1 mm) led to a SR140333B-sensitive contralateral deflection in the presence of systemic haloperidol administration. Combining electrophysiological and behavioural findings, we concluded that substance P produces excitatory effects on globus pallidus neurons via neurokinin-1 receptors.
Cui
Qiao-Ling
QL
Department of Physiology, Faculty of Medicine, Qingdao University, Qingdao, Shandong, China.
Yung
Wing-Ho
WH
Xue
Yan
Y
Chen
Lei
L
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D018492:Dopamine Antagonists / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D005917:Globus Pallidus / Q000166:cytology* / Q000187:drug effects; D006220:Haloperidol / Q000494:pharmacology; D008297:Male; D064729:Neurokinin-1 Receptor Antagonists; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D018377:Neurotransmitter Agents / Q000494:pharmacology*; D011187:Posture; D051381:Rats; D017208:Rats, Wistar; D018040:Receptors, Neurokinin-1 / Q000819:agonists / Q000502:physiology; D013373:Substance P / Q000031:analogs & derivatives / Q000494:pharmacology*; D014326:Tropanes / Q000494:pharmacology
D018492:Dopamine Antagonists; D064729:Neurokinin-1 Receptor Antagonists; D018377:Neurotransmitter Agents; D018040:Receptors, Neurokinin-1; C526005:SR140333B; D014326:Tropanes; C062618:substance P, Sar(9)-Met(O2)(11)-; D013373:Substance P; D002795:Choline O-Acetyltransferase; D006220:Haloperidol