PT - JOURNAL ARTICLE AU - Schnee, M AU - Rauh, J AU - Buckingham, S D AU - Sattelle, D B TI - Pharmacology of skeletal muscle GABA-gated chloride channels in the cockroach Periplaneta americana. DP - 1997 Dec 01 TA - The Journal of Experimental Biology PG - 2947--2955 VI - 200 IP - 23 4099 - http://jeb.biologists.org/content/200/23/2947.short 4100 - http://jeb.biologists.org/content/200/23/2947.full SO - J. Exp. Biol.1997 Dec 01; 200 AB - The pharmacology of -aminobutyric acid (GABA)-gated chloride channels of the coxal levator (182c,d) muscle of the cockroach Periplaneta americana has been investigated and the data compared with similar findings for the cell body of the cockroach fast coxal depressor motor neurone (Df). Muscle GABA receptors resembled those of the motor neurone cell body in their sensitivity to picrotoxinin and insensitivity to bicuculline. However, muscle GABA receptors were insensitive to the neuronal GABA receptor agonists isoguvacine (10(-4) mol l-1) and 3-aminopropane sulphonic acid (10(-3 )mol l-1). The benzodiazepine flunitrazepam, which at 10(-6 )mol l-1 greatly enhances the amplitude of the motor neurone GABA-induced responses, failed to affect muscle responses to GABA when tested at the same and at a higher (10(-4 )mol l-1) concentration. The convulsant t-butylbicyclophosphorothionate was a weak antagonist of cockroach muscle GABA receptors, whereas several cyclodienes were much more effective antagonists. Thus, studies using a benzodiazepine and several convulsant antagonists reveal differences in the pharmacology of muscle and neuronal GABA receptors of the cockroach Periplaneta americana.