title: Dopamine-dependent modulation of rat globus pallidus excitation by nicotine acetylcholine receptors.
abstract: The globus pallidus (GP) coordinates information processing in the basal ganglia nuclei. The contribution of nicotinic cholinergic receptors (nAChRs) to the spiking activity of GP neurons is largely unknown. Several studies have reported that the effect of nAChRs in other nuclei depends on dopaminergic input. Via in vivo single unit extracellular recordings and intranuclear drug infusions, we analyzed the effects of local activation and blockade of nAChRs in neurons of both sham and 6-hydroxydopamine (6-OHDA)-lesioned rats. In sham rats, the local application of nicotine and edrophonium (an acetylcholinesterase inhibitor) increases GP neurons spiking rate. Local application of mecamylamine, a neuronal nicotinic cholinergic antagonist, diminishes pallidal neurons spiking rate, an effect not produced by d-tubocurarine, a peripheral nicotinic cholinergic antagonist. Moreover, mecamylamine blocks the excitatory effect evoked by nicotine and edrophonium. In 6-OHDA-lesioned rats, local infusion of nicotine does not change pallidal neurons firing rate. Our results show that there is a tonic cholinergic input to the GP that increases their spiking rate through the activation of nAChRs and that this effect depends on functional dopaminergic pathways.
authors.affiliation: Academia de Fisiología, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, Colonia Casco de Santo Tomás, 11340, Mexico, D.F., Mexico.
authors.forename: Alain
authors.initials: A
authors.lastname: Ríos
authors.affiliation: Academia de Fisiología, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, Colonia Casco de Santo Tomás, 11340, Mexico, D.F., Mexico.
authors.forename: Rafael
authors.initials: R
authors.lastname: Barrientos
authors.affiliation: Academia de Fisiología, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, Colonia Casco de Santo Tomás, 11340, Mexico, D.F., Mexico.
authors.forename: Alberto
authors.initials: A
authors.lastname: Alatorre
authors.affiliation: Departamento de Fisiología Experimental, Facultad de Medicina y Ciencias Biomédicas, Universidad Autónoma de Chihuahua, Circuito Universitario Campus II, 31127, Chihuahua, Chih., Mexico.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Delgado
authors.affiliation: Academia de Fisiología, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, Colonia Casco de Santo Tomás, 11340, Mexico, D.F., Mexico.
authors.forename: Teresa
authors.initials: T
authors.lastname: Perez-Capistran
authors.affiliation: Departamento de Fisiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Wilfrido Massieu SN, Unidad profesional Adolfo López Mateos, Col. Planetario Zacatenco, 07738, Mexico, D.F., Mexico.
authors.forename: Eliezer
authors.initials: E
authors.lastname: Chuc-Meza
authors.affiliation: Departamento de Fisiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Wilfrido Massieu SN, Unidad profesional Adolfo López Mateos, Col. Planetario Zacatenco, 07738, Mexico, D.F., Mexico.
authors.forename: Martha
authors.initials: M
authors.lastname: García-Ramirez
authors.affiliation: Sección de Investigación y Posgrado de la Escuela Superior de Medicina del IPN, Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón, Colonia Casco de Santo Tomás, 11340, Mexico, D.F., Mexico. equerejeta@ipn.mx.
authors.forename: Enrique
authors.initials: E
authors.lastname: Querejeta
mesh_terms: D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D004298:Dopamine / Q000502:physiology*; D005917:Globus Pallidus / Q000187:drug effects / Q000502:physiology*; D008297:Male; D009538:Nicotine / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011978:Receptors, Nicotinic / Q000502:physiology*
chemical_list: D011978:Receptors, Nicotinic; D009538:Nicotine; D004298:Dopamine
keywords: Basal ganglia; Dopamine; Electrical activity; Globus pallidus; Nicotine receptors