Benzodiazepine temazepam suppresses the transient auditory 40-Hz response amplitude in humans

To discern the role of the GABAA receptors in the generation and attentive modulation of the transient auditory 40-Hz response, the effects of the ben zodiazepine temazepam (10 mg) were studied in 10 healthy social drinkers, u sing a double-blind placebo-controlled design. Three hundred Hertz standard and 330 Hz rare deviant tones were presented to the left, and 1000 Hz stan dards and 1100 Hz deviants to the right ear of the subjects. Subjects atten ded to a designated ear and were to detect deviants therein while ignoring tones to the other. Temazepam significantly suppressed the amplitude of the 40-Hz response, the effect being equal for attended and non-attended tone responses. This suggests involvement of GABAA receptors in transient audito ry 40-Hz response generation, however, not in the attentive modulation of t he 40-Hz response. (C) 1999 Elsevier Science Ireland Ltd. All rights reserv ed.