GABA and chloride permeate via the same channels across single plasma membranes microdissected from rabbit Deiters' vestibular neurones.
The permeation of labelled gamma-aminobutyric acid (GABA) across single microdissected Deiters' membranes has been studied in a microchamber system. The GABA permeation is via pores which are blocked by 4,4'-diisothiocyanato stilbene-2-2'disulphonic acid (DIDS). As this substance blocks as well chloride permeation across these membranes we tested whether GABA and chloride permeate across the same pores. Membrane pre-treatment with different doses of corticotropin releasing factor (CRF), a membrane permeant cyclic AMP analogue and phalloidin parallelly block the permeation of the two substances. Thus, it is most probable that GABA and chloride pass across the same pores. These pores may be swelling activated ones, opened by the mechanical stress on the membranes in the microchamber system. The passage of GABA across these pores may be of physiological importance in the termination of GABA inhibitory action on the vestibular Deiters' neurones.
Rapallino
M V
MV
Centro di Neurofisiologia Cerebrale, C.N.R. Genova, Italy.
Cupello
A
A
D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000494:pharmacology; D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport / Q000187:drug effects / Q000502:physiology; D002462:Cell Membrane / Q000378:metabolism*; D018118:Chloride Channels / Q000378:metabolism; D002712:Chlorides / Q000493:pharmacokinetics*; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology; D015194:Diffusion Chambers, Culture; D066298:In Vitro Techniques; D008297:Male; D009474:Neurons / Q000378:metabolism*; D011817:Rabbits; D014316:Tritium; D003689:Vestibular Nucleus, Lateral / Q000166:cytology* / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000493:pharmacokinetics*
D018118:Chloride Channels; D002712:Chlorides; D014316:Tritium; D015124:8-Bromo Cyclic Adenosine Monophosphate; D005680:gamma-Aminobutyric Acid; D003346:Corticotropin-Releasing Hormone; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid