Modulation of noise-potentiated acoustic startle via the benzodiazepine--gamma-aminobutyric acid receptor complex.
Diazepam (DZ), an anxiolytic benzodiazepine (BZD) compound, attenuated the facilitation of the acoustic startle response by background noise. In Experiment 1, using a cumulative dosing paradigm, the effect of DZ on noise potentiation was found to be dose related. In Experiment 2, using a between-animals exposure design, the effect of DZ on noise potentiation was attenuated by coexposure to the central-type BZD receptor antagonist RO 15-1788, which itself was without effect. Using a cumulative dosing design in Experiment 3, RO 15-1788 was found to reverse the effect of DZ, whereas the peripheral-type BZD receptor ligand RO 54864 was without effect. The differences in the effect of cumulative exposure versus single dose exposure to RO 15-1788 were interpreted as indicative of either an intrinsic effect of the antagonist after repeated exposure or an influence of background noise itself on the BZD-gamma-aminobutyric acid receptor complex.
Kellogg
C K
CK
Department of Psychology, University of Rochester, New York 14627.
Sullivan
A T
AT
Bitran
D
D
Ison
J R
JR
D000161:Acoustic Stimulation; D000818:Animals; D001307:Auditory Perception / Q000187:drug effects*; D001570:Benzodiazepinones / Q000494:pharmacology; D001921:Brain / Q000187:drug effects*; D003292:Convulsants / Q000494:pharmacology; D003975:Diazepam / Q000494:pharmacology*; D005442:Flumazenil / Q000494:pharmacology; D058787:GABA-A Receptor Antagonists; D008297:Male; D009474:Neurons / Q000187:drug effects; D051381:Rats; D011963:Receptors, GABA-A / Q000187:drug effects*; D013216:Reflex, Startle / Q000187:drug effects*
D001570:Benzodiazepinones; D003292:Convulsants; D058787:GABA-A Receptor Antagonists; D011963:Receptors, GABA-A; C028513:4'-chlorodiazepam; D005442:Flumazenil; D003975:Diazepam