title: GABAergic projection from the ventral pallidum and globus pallidus to the subthalamic nucleus.
abstract: There exists a topographically organized projection from the globus pallidus and ventral pallidum to the subthalamic nucleus and adjacent lateral hypothalamus. The participation of GABA as a neurotransmitter in this projection was evaluated by retrograde labeling of cells in the pallidal area from an iontophoretic deposit of Fluor-Gold in the subthalamus combined with in situ hybridization for mRNA of the GABA synthetic enzyme, glutamate decarboxylase (GAD). A rostrocaudal gradient in the contribution of GABA to the projection was demonstrated with a relatively small percentage of retrogradely labeled cells in the rostral ventral pallidum containing GAD mRNA (7%) compared to the caudal globus pallidus which had over 70% of the Fluoro-Gold containing cells double-labeled for GAD mRNA. Overall the ventral pallidum contribution to the subthalamic nucleus was less GABAergic than the portion arising from the globus pallidus (35% vs. 61%, respectively).
authors.affiliation: Alcohol and Drug Abuse Program, Washington State University, Pullman 99164-6520, USA.
authors.forename: K
authors.initials: K
authors.lastname: Bell
authors.forename: L
authors.initials: L
authors.lastname: Churchill
authors.forename: P W
authors.initials: PW
authors.lastname: Kalivas
mesh_terms: D000818:Animals; D004745:Enkephalins / Q000378:metabolism; D005456:Fluorescent Dyes; D005917:Globus Pallidus / Q000166:cytology / Q000502:physiology*; D005968:Glutamate Decarboxylase / Q000378:metabolism; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D007478:Iontophoresis; D008297:Male; D009434:Neural Pathways / Q000166:cytology / Q000502:physiology; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D013266:Stilbamidines; D013787:Thalamic Nuclei / Q000166:cytology / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000502:physiology*
chemical_list: C049774:2-hydroxy-4,4'-diamidinostilbene, methanesulfonate salt; D004745:Enkephalins; D005456:Fluorescent Dyes; D012333:RNA, Messenger; D013266:Stilbamidines; D005680:gamma-Aminobutyric Acid; D005968:Glutamate Decarboxylase