title: On the relationships of high-frequency hearing loss and cochlear pathology to the acoustic startle response (ASR) and prepulse inhibition of the ASR in the BXD recombinant inbred series.
abstract: The measurement of the acoustic startle response (ASR) and prepulse inhibition (PPI) of the ASR in many inbred strains of mice, including C57BL/6 and DBA/2, may be complicated by age-related high-frequency hearing loss (HFHL) and the associated cochlear pathology. Willott and Erway (1998) have recently reported on the age-related changes of the acoustic brain response in the BXD recombinant inbred (RI) series. Based on these data, the RI series was divided into three groups: juvenile-, intermediate-, and adult-onset HFHL. Each of these groups was tested using paradigms which varied the frequency or intensity of the auditory startle and prepulse stimuli. The results obtained in adolescent mice (6-8 weeks) demonstrate that ASR performance is independent of HFHL; there was no group-dependent decline in the ASR amplitudes for high-frequency stimuli. The expected effect of HFHL on PPI is to increase the salience of the still-audible tones. In response to a white-noise prepulse stimulus, the PPI in the juvenile-onset group (which shows marked HFHL at 6 weeks) was similar to that in the adult-onset group. However, when the prepulse stimulus was a pure tone, the juvenile group showed a decrease in salience across all frequencies tested (5-20 kHz). The data point out the need for carefully constructing auditory tasks in the BXD RI series, to avoid the confounding effects of HFHL.
authors.affiliation: Department of Psychiatry, SUNY at Stony Brook 11794-8101, USA.
authors.forename: J
authors.initials: J
authors.lastname: McCaughran
authors.forename: J
authors.initials: J
authors.lastname: Bell
authors.forename: R
authors.initials: R
authors.lastname: Hitzemann
mesh_terms: D000161:Acoustic Stimulation; D000375:Aging / Q000235:genetics; D000704:Analysis of Variance; D000818:Animals; D015834:Cochlear Diseases / Q000235:genetics / Q000473:pathology; D003463:Cues; D005260:Female; D006311:Hearing Disorders / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains / Q000502:physiology*; D008822:Mice, Transgenic / Q000502:physiology*; D009433:Neural Inhibition / Q000235:genetics* / Q000502:physiology; D013216:Reflex, Startle / Q000235:genetics* / Q000502:physiology