title: Audiograms, gap detection thresholds, and frequency difference limens in cannabinoid receptor 1 knockout mice.
abstract: The cannabinoid receptor 1 (CB1R) is found at several stages in the auditory pathway, but its role in hearing is unknown. Hearing abilities were measured in CB1R knockout mice and compared to those of wild-type mice. Operant conditioning and the psychophysical Method of Constant Stimuli were used to measure audiograms, gap detection thresholds, and frequency difference limens in trained mice using the same methods and stimuli as in previous experiments. CB1R knockout mice showed deficits at frequencies above 8 kHz in their audiograms relative to wild-type mice. CB1R knockouts showed enhancements for detecting gaps in low-pass noisebursts relative to wild-type mice, but were similar for other noise conditions. Finally, the two groups of mice did not differ in their frequency discrimination abilities as measured by the frequency difference limens task. These experiments suggest that the CB1R is involved in auditory processing and lay the groundwork for future physiological experiments.
authors.affiliation: Department of Psychology, University at Buffalo SUNY, Buffalo, NY 14260, USA. Electronic address: ktoal@buffalo.edu.
authors.forename: Katrina L
authors.initials: KL
authors.lastname: Toal
authors.affiliation: Department of Psychology, University at Buffalo SUNY, Buffalo, NY 14260, USA. Electronic address: radziwon@buffalo.edu.
authors.forename: Kelly E
authors.initials: KE
authors.lastname: Radziwon
authors.affiliation: Department of Psychology, University at Buffalo SUNY, Buffalo, NY 14260, USA. Electronic address: davidhol@buffalo.edu.
authors.forename: David P
authors.initials: DP
authors.lastname: Holfoth
authors.affiliation: Department of Biological Sciences, University at Buffalo SUNY, Buffalo, NY 14260, USA. Electronic address: mx@buffalo.edu.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Xu-Friedman
authors.affiliation: Department of Psychology, University at Buffalo SUNY, Buffalo, NY 14260, USA. Electronic address: mdent@buffalo.edu.
authors.forename: Micheal L
authors.initials: ML
authors.lastname: Dent
mesh_terms: D000161:Acoustic Stimulation; D000818:Animals; D001301:Audiometry, Pure-Tone; D001306:Auditory Pathways / Q000378:metabolism* / Q000503:physiopathology; D001307:Auditory Perception; D001522:Behavior, Animal; D003216:Conditioning, Operant; D003463:Cues; D005838:Genotype; D008808:Mice, Inbred CBA; D018345:Mice, Knockout; D009622:Noise / Q000009:adverse effects; D010470:Perceptual Masking; D010641:Phenotype; D010898:Pitch Perception; D043884:Receptor, Cannabinoid, CB1 / Q000172:deficiency* / Q000235:genetics; D017603:Signal Detection, Psychological; D013997:Time Factors
chemical_list: C578453:CNR1 protein, mouse; D043884:Receptor, Cannabinoid, CB1
keywords: Audiogram; CB1R KO; CBA/CaJ; Difference limens; Gap detection; Mouse