caa a22 4500 469119101 CHVBK 20180323133133.0 cr unu---uuuuu 170328e19921001xx s 000 0 eng 10.1007/BF02245482 doi (NATIONALLICENCE)springer-10.1007/BF02245482 Specific effects of the benzodiazepine midazolam on visual receptive fields in light and dark adapted human subjects [Elektronische Daten] [M. Groner, H. Fisch, F. Walder, R. Groner, D. Hofer, U. Koelbing, I. Duss, R. Bianchi, B. Bircher] Psychophysical experiments in humans have revealed similar characteristics of visual receptive fields as were found in cats and monkeys from retinal ganglion cell recordings. In addition, in some retinal ganglion cells of cats the GABA antagonist bicuculline decreases the activity of the inhibitory surround. These findings led to two predicitions: 1) benzodiazepines will selectively increase the inhibitory surround of human visual receptive fields, 2) after dark adaptation, no free GABA will be available in the synapses and benzodiazepines will have no effect on the visual system. Characteristics of human receptive fields were determined by subthreshold summation: the contrast threshold of a vertical line was measured dependent on the distance of two parallel flanking lines whose contrast was below threshold. Both hypotheses were confirmed: the threshold in the inhibitory region of receptive fields was specifically increased in a dose-dependent manner by midazolam PO (7.5 mg:P<0.05; 15 mg:P<0.01). In dark-adapted subjects no effect of midazolam was found. Control experiments with atropine (1 mg IV), sulpiride (100 mg IM), and levodopa (100 mg PO) showed no specific effect. The visual system may be a model to bridge the gap between animal and human psychopharmacology. Springer-Verlag, 1992 Visual system nationallicence Visual receptive fields nationallicence Subthreshold summation nationallicence Shift effect nationallicence Dark adaptation nationallicence Benzodiazepines nationallicence GABA nationallicence Bicuculline nationallicence Dopamine nationallicence Levodopa nationallicence Sulpiride nationallicence Atropine nationallicence Human nationallicence Cat nationallicence Psychophysics nationallicence Groner M. Department of Psychology, University of Berne, CH-3010, Berne, Switzerland aut Fisch H. Department of Psychiatry, University of Berne, CH-3010, Berne, Switzerland aut Walder F. Department of Psychology, University of Berne, CH-3010, Berne, Switzerland aut Groner R. Department of Psychology, University of Berne, CH-3010, Berne, Switzerland aut Hofer D. Department of Psychology, University of Berne, CH-3010, Berne, Switzerland aut Koelbing U. Department of Psychiatry, University of Berne, CH-3010, Berne, Switzerland aut Duss I. Department of Psychiatry, University of Berne, CH-3010, Berne, Switzerland aut Bianchi R. Department of Psychiatry, University of Berne, CH-3010, Berne, Switzerland aut Bircher B. Department of Psychiatry, University of Berne, CH-3010, Berne, Switzerland aut Psychopharmacology Springer-Verlag 109/1-2(1992-10-01), 68-76 0033-3158 109:1-2<68 1992 109 213 https://doi.org/10.1007/BF02245482 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02245482 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Groner M. Department of Psychology, University of Berne, CH-3010, Berne, Switzerland aut NATIONALLICENCE 700 1- Fisch H. Department of Psychiatry, University of Berne, CH-3010, Berne, Switzerland aut NATIONALLICENCE 700 1- Walder F. Department of Psychology, University of Berne, CH-3010, Berne, Switzerland aut NATIONALLICENCE 700 1- Groner R. Department of Psychology, University of Berne, CH-3010, Berne, Switzerland aut NATIONALLICENCE 700 1- Hofer D. Department of Psychology, University of Berne, CH-3010, Berne, Switzerland aut NATIONALLICENCE 700 1- Koelbing U. Department of Psychiatry, University of Berne, CH-3010, Berne, Switzerland aut NATIONALLICENCE 700 1- Duss I. Department of Psychiatry, University of Berne, CH-3010, Berne, Switzerland aut NATIONALLICENCE 700 1- Bianchi R. Department of Psychiatry, University of Berne, CH-3010, Berne, Switzerland aut NATIONALLICENCE 700 1- Bircher B. Department of Psychiatry, University of Berne, CH-3010, Berne, Switzerland aut NATIONALLICENCE 773 0- Psychopharmacology Springer-Verlag 109/1-2(1992-10-01), 68-76 0033-3158 109:1-2<68 1992 109 213 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer