Penicillin decreases chloride conductance in crustacean muscle: a model for the epileptic neuron

• Published in: Brain research Vol. 107; no. 1; p. 85
• Main Authors: Hochner, B, Spira, M E, Werman, R
• Format: Journal Article
• Language: English
• Published: Netherlands 30-04-1976
• Subjects: Animals; Brachyura; Cell Membrane - drug effects; Chlorides - metabolism; Disease Models, Animal; Dose-Response Relationship, Drug; Epilepsy - chemically induced; Epilepsy - metabolism; GABA Antagonists; gamma-Aminobutyric Acid - pharmacology; Glutamates - pharmacology; In Vitro Techniques; Membrane Potentials - drug effects; Muscles - drug effects; Neural Conduction - drug effects; Neuromuscular Junction - drug effects; Neurons - metabolism; Penicillin G - pharmacology; Receptors, Cholinergic - drug effects; Synaptic Membranes - drug effects; Synaptic Transmission - drug effects
• ISSN: 0006-8993
• DOI: 10.1016/0006-8993(76)90097-4

The effects of penicillin were studied on the neuromuscular preparation of the ghost crab, Ocypoda cursor. Penicillin in doses lower than 2 mM reduced both the amplitude of inhibitory junction potentials and conductance increases induced by external application of GABA. The nature of the latter effect appears to be 2-fold, a weaker competitive inhibition and a more powerful non-competitive effech which may be ionophore blockade. Penicillin in concentrations above 2 mM diminished resting conductance, especially that of chloride. The action of penicillin is, in general, to decrease chloride conductance in this preparation. The crustacean neuromuscular preparation may provide a useful analogue for understanding penicillin evoked epilepsy. The reduced chloride conductance could explain decreased inhibition, increased excitation and depolarization shifts in cortical neurons.