GABA-ergic control of visual perception in healthy volunteers: effects of midazolam, a benzodiazepine, on spatio-temporal contrast sensitivity.

摘要: 1. We studied the effects of midazolam (MDZ), a benzodiazepine, on spatio-temporal contrast sensitivity, choice reaction time, and mood visual analogue scales in healthy volunteers. 2. Eight extensively trained, volunteers were included placebo-controlled cross-over double-blind trial MDZ (0.15 mg kg-1). Treatments injected intramuscularly evaluations performed before 0.5, 1, 2, 3 4 h after drug administration. Spatio-temporal sensitivity was measured using micro-computer with appropriate software. Stimuli vertical gratings adjustable contrast, spatial frequencies 0.25, 1 cpd. Four conditions temporal modulation used: grating either static or drifting laterally 9 Hz. 3. An analysis variance data. As compared placebo, induced an increase time sedation (as assessed scales). From 0.5-4 injection, produced overall decrease as placebo. More specifically, preferentially affected medium to high low frequencies. Several non-exclusive hypotheses may account for results: 1) size receptive fields, 2) preferential effect parvocellular pathways which mediate