GABAA and GABAB receptors differentially regulate striatal acetylcholine release in vivo.
Microdialysis was used to study the effects of selective GABAergic agents on striatal acetylcholine (ACh) release in awake, freely moving rats. Local perfusion with the GABAA agonist muscimol dramatically reduced striatal ACh release, while the GABAB agonist baclofen caused only minor decreases in ACh release. Co-perfusion with the GABAA antagonist bicuculline diminished the muscimol-induced decrease in ACh release. Likewise, co-perfusion with the GABAB antagonist 2-hydroxysaclofen attenuated the baclofen-induced reduction in ACh release. Bicuculline alone markedly increased striatal ACh release, but 2-hydroxysaclofen by itself had no effect. These results suggest that GABA tonically regulates striatal ACh release primarily through stimulation of inhibitory GABAA receptors.
Anderson
J J
JJ
Experimental Therapeutics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892.
Kuo
S
S
Chase
T N
TN
Engber
T M
TM
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D001418:Baclofen / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology*; D001640:Bicuculline / Q000008:administration & dosage / Q000494:pharmacology; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D058787:GABA-A Receptor Antagonists; D058788:GABA-B Receptor Antagonists; D007700:Kinetics; D008297:Male; D017551:Microdialysis; D009118:Muscimol / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011963:Receptors, GABA-A / Q000502:physiology*; D018080:Receptors, GABA-B / Q000502:physiology*; D013238:Stereotaxic Techniques; D013997:Time Factors
D058787:GABA-A Receptor Antagonists; D058788:GABA-B Receptor Antagonists; D011963:Receptors, GABA-A; D018080:Receptors, GABA-B; D009118:Muscimol; D001418:Baclofen; D000109:Acetylcholine; C057491:2-hydroxysaclofen; D001640:Bicuculline