Elsevier

Neurotoxicology and Teratology

Volume 12, Issue 1, January–February 1990, Pages 7-14
Neurotoxicology and Teratology

Microanalysis of ultrasound vocalizations of young rats: Assessment of the behavioral teratogenicity of methylmercury

https://doi.org/10.1016/0892-0362(90)90106-MGet rights and content

Abstract

An on-line real-time computer system for the analysis of ultrasound vocalizations of rats is presented. The calls of young rats are recorded by an ultrasound microphone, transformed by an amplitude envelope and a frequency to voltage converter, digitized and stored by a microcomputer. The data management and analysis of the recorded vocalizations are entirely automated, allowing a high throughput of experiments in a routine laboratory. The frequency values are analyzed with respect to number, duration, base-interval, and mean frequency of the calls. Also, the frequency distributions of the call to call intervals, the call durations and the ultrasound frequencies, as well as the power spectra of the frequency modulations, are calculated. This system was used for the assessment of the behavioral teratogenicity of methylmercury chloride. Wistar rat dams were treated with 0, 1.5 or 5 mg/l in their drinking water from two weeks prior to pairing until the end of the experiment. The ultrasound vocalizations of two female and two male offspring per litter were recorded on days 5, 7, 9, 11, 13, and 15 for one minute in a clean glass beaker cooled to 20°C. Methylmercury treatment resulted in a developmental delay and an overall reduction in the number of calls, a shortening of the base-interval and the call durations, a flattening and shift of the frequency distributions, and an alteration in the development with age of the frequency distributions. The frequency modulations of the calls also differed, their power being lower (smaller frequency variation) on several occasions.

References (39)

  • J.T. Allin et al.

    Effects of temperature on ultrasound production by infant albino rats

    Dev. Psychobiol.

    (1971)
  • A. Amsel et al.

    Ultrasound emission in infant rats as an indicant of arousal during appetitive learning and extinction

    Science

    (1977)
  • R. Bell

    Ultrasound in small rodents: arousal produced and arousal producing

    Dev. Psychobiol.

    (1974)
  • J. Buelke-Sam et al.

    Development and standardization of screening methods for behavioral teratology

    Teratology

    (1979)
  • J.H. Burkholder et al.

    A broadband digitizing rat detector: Simultaneous recording from all sound frequencies in the range of rat ultrasound vocalizations

    Behav. Res. Method Instr.

    (1982)
  • R.E. Butcher et al.

    A preliminary test battery for the investigation of the behavioral teratology of selected psychotropic drugs

    Neurobehav. Toxicol.

    (1979)
  • L. Conely et al.

    Neonatal ultrasounds elicited by odor cues

    Dev. Psychobiol.

    (1978)
  • M. Davidson et al.

    General univariate and multivariate analysis of variance and covariance, including repeated measures (URWAS)

  • J. Elsner

    PASTOR, a new schedule programming language

    Behav. Res. Methods Instr.

    (1982)
  • Cited by (0)

    This work was supported in part by grant No. 3.058-0.81 from the Swiss National Foundation.

    2

    D. Suter is now at Perkin-Elmer AG, Kohlrainstrasse 10, CH-8700 Küsnacht, Switzerland.

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