Anion permeability of the inhibitory post‐synaptic membrane of the crayfish neuromuscular junction

TLDR

Let's gather content. Other: line "[Other] 1." That's just "1."? The content is "1." maybe just a placeholder. It seems minimal.

Abstract

1. The membrane conductance of the crayfish muscle fibre was calculated and the increase in the membrane conductance brought about by the application of gamma-aminobutyric acid (GABA) was investigated under various conditions. The permeability of the activated inhibitory post-synaptic membrane was estimated from the conductance change.2. When the concentration of Cl(-) was changed by substituting Cl(-) with methylsulphate, a linear relation was obtained between the membrane conductance change produced by GABA and the concentration of Cl(-). Cations have no appreciable effect on the GABA induced conductance change (less than 0.4%).3. The conductance change produced by GABA on the inhibitory post-synaptic membrane was measured in various solutions in which the Cl(-) was replaced by various anions. The degree of permeability depended on the anion species in the following order:Br(-) > Cl(-) > SCN(-) > I(-) > NO(3) (-) > HCOO(-) > ClO(3) (-) > ClO(4) (-) > BrO(3) (-)4. At high pH the conductance change produced by GABA was decreased, while at low pH it increased.5. These results show that the activated inhibitory post-synaptic membrane of crayfish muscle fibres has the characteristics of an anion selective membrane, suggesting the fixed positive charges in the inhibitory membrane.