Diphenylhydantoin prolongs postsynaptic inhibition and iontophoretic GABA action in the crayfish stretch receptor.
The action of diphenylhydantoin (DPH) was studied in the crayfish stretch receptor on the IPSP evoked by efferent fibre stimulation and on the conductance and potential changes produced by local iontophoresis of GABA. DPH caused a prolongation of these transients. DPH prevented the blockade by picrotoxin of postsynaptic inhibition and of GABA responses. These findings suggest a postsynaptic site of action of DPH close to the GABA-mediated chloride conductance mechanism.
Deisz
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RA
Max-Planck-Institute for Psychiatry, Department of Neurophysiology, Kraepelinstrasse 2, D-8000 München 40 G.F.R.
Lux
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HD