Bicuculline, benzyl penicillin, and inhibitory amino acids in the spinal cord of the cat.

摘要: Bicuculline methochloride (BMC), applied by microiontophoresis, tends to depolarize spinal motoneurons and lower their input resistance. With approximately equal iontophoretic currents of gamma-aminobutyric acid (GABA) BMC, there is an almost chance observing no change, a potentiation, or depression the GABA-evoked conductance increase. A block GABA action seen consistently only when current BMC at least double that GABA. Under these conditions can selectively antagonize without blocking effects glycine, though latter also be blocked larger amounts BMC. regularly eliminates usual apparent desensitization This may due uptake which would account for its potentiating relative doses. Comparable are observed with applications benzyl penicillin (BP); but even large doses BP produce definite change in membrane properties increase evoked glycine.