In article <341FCECC.1FBA at c220.unimo.it>, bigiani at c220.unimo.it
>I have a question about a recent paper showing a conductance increase
>for GABAa receptors induced by benzodiazepines. Does anybody know
>additional literature is available on this topic?
Well Albertino, I think the reason that paper got into Nature is because
they were the first, and as far as I know the only, group to demonstrate
an increase in conductance by benzodiazepines. Previous reports in the
literature suggested that benzodiazepines affect the frequency of channel
opening but not conductance. In case you're interested, here are some
other papers which did NOT show an increase in conductance by
Poncer JC. et al., Modulation of synaptic GABAA receptor function by
benzodiazepines in area CA3 of rat hippocampal slice cultures.
Neuropharmacol. 35:1169-1179, 1996.
Rogers CJ. et al., Benzodiazepine and beta-carboline regulation of single
GABAA receptor channels of mouse spinal neurones in culture. J.
Physiol. 475:69-82, 1994.
MacDonald RL and Twyman RE, Kinetic properties and regulation of
GABAA receptor channels. Ion Channels. 3:315-343, 1992. This is a
Vicini S. et al., Actions of benzodiazepine and beta-carboline derivatives
on gamma-aminobutyric acid-activated Cl- channels recorded from
membrane patches of neonatal rat cortical neurons in culture. J.
Pharmacol. Exp. Ther. 243:1195-1201, 1987.
S. John Mihic, Ph.D.
Dept. Physiology & Pharmacology
Bowman Gray School of Medicine of Wake Forest University
Winston-Salem, NC 27157