CHARACTERIZATION OF THE BINDING OF [³H]MUSCIMOL, A POTENT γ‐AMINOBUTYRIC ACID AGONIST, TO RAT BRAIN SYNAPTOSOMAL MEMBRANES USING A FILTRATION ASSAY

Abstract

Abstract— The binding of [3H]muscimol, a potent GABA agonist, to crude synaptic membranes prepared from rat brain was studied using a filtration method to isolate membrane‐bound ligand. Specific binding was found to be saturable and occurred to two binding sites of Kd5 5 and 30 nm. Binding was Na+‐independent and enhanced by both freezing and Triton treatment. Regional and subcellular distribution studies and pharmacological characterization of specific [3H]muscimol binding are consistent with binding to the synaptic GABA receptor.

Enhanced muscimol-induced behavioral responses after 6-OHDA lesions: relevance to susceptibility for self-mutilation behavior in neonatally lesioned rats

“…In the present work, bilateral administration of muscimol to neonatal and adult-6-OHDA-lesioned rats resulted in a differing incidence of SMB and of other behaviors observed when muscimol was microinjected bilaterally into the SNR. Thus, the differences in behavioral responses observed after administering dopamine agonists to neonatal and adult 6-OHDAlesioned rats also extend to the responses observed after administering muscimol into the SNR.At the present time, it is believed that muscimol acts on GABA receptors (Williams and Risley 1979). If this is the case, one would expect bicuculline, a GABA antagonist, to antagonize the SMB induced by muscimol microinjection into the SNR.…”

“…At the present time, it is believed that muscimol acts on GABA receptors (Williams and Risley 1979). If this is the case, one would expect bicuculline, a GABA antagonist, to antagonize the SMB induced by muscimol microinjection into the SNR.…”

BINDING OF [3H]‐MUSCIMOL, A POTENT γ‐AMINOBUTYRIC ACID RECEPTOR AGONIST, TO MEMBRANES OF THE BOVINE RETINA

“…The resultant supernatant was then centrifuged at 800 g for 10 min to obtain a P1 pellet which was shown by Redburn (1977) to be highly rich in photoreceptor cell synaptosomes. Centrifugation of the supernatant at 25,000 g for 12 min produced a pellet P2 which contains synaptosomes derived from the inner plexiform layer (Redburn, 1977 (1978), Williams & Risley (1979), Snodgrass (1978) and Wang et al (1979). The radioligand binds specifically in a saturable manner at low concentrations to two binding sites and is slightly enhanced by freezing and treatment with Triton X-100.…”

“…More recently, the potent GABA receptor agonist, muscimol, has become available as a radioligand and has been used by a number of workers to characterize the synaptic GABA receptor in the mammalian brain (Beaumont, Chilton, Yamamura & Enna, 1978;Snodgrass, 1978;Williams & Risley 1979). Muscimol has a higher affinity for the GABA receptor than GABA itself and apparently labels the receptor rather than the uptake sites (see Johnston, 1978;Williams & Risley, 1979).…”

“…Muscimol has a higher affinity for the GABA receptor than GABA itself and apparently labels the receptor rather than the uptake sites (see Johnston, 1978;Williams & Risley, 1979).…”