GABA_A Receptor Complexes are Present on Both Sides of a Gaba-Acceptive Neuronal Membrane

Abstract

A micromethod allowing the study of the characteristics of single GABA-acceptive membranes microdissected from Deiters' neurones was used in order to assess the effects of both “extra”- and “intra”-cellular GABA on Cl⁻ permeability. The results indicate that GABA can activate Cl⁻ permeability in the in out direction when it is present on the cytoplasmic side of the membrane. Moreover, as already described, it can activate Cl⁻ permeability in the opposite direction when present on the “extracellular” side of the membrane. Both these phenomena are blocked by GABA^A receptor inhibitors, bicuculline and picrotoxin. The presence of GABA^A receptors on both sides of the membrane is discussed as the possible basis for synaptically released GABA hyperpolarising action on these neurones.

Key Words:

• GABA^A receptors
• Deiters' membrane
• GABA
• hyperpolarization
• inhibition

Additional information

Notes on contributors

Aroldo Cupello

Joyce Laing works in the Department of Child and Family Psychiatry, Playfield House, Cupar, Fife, and is a Consultant Art Therapist to Psychiatric Hospitals and Prisons and Chairwoman of the Scottish Society of Art and Psychology.