Abstract
In order to determine the effect of time of day on reflex modification, we measured the acoustic startle reflex (ASR) in rats (n = 4) to 120-dB tone bursts given alone to provide the ASR baseline, 100 msec after an inhibiting brief noise prepulse, or 10 to 20 sec after the onset of a facilitating noise background for 4–5 days in a test environment illuminated on a 12:12-h light:dark cycle. ASR amplitudes were greater in the dark, and sinusoids with a 24-h period starting at the light:dark transition accounted for about 80% of the variance in ASR amplitudes within each stimulus condition. The absolute differences in amplitude between baseline and either inhibited or facilitated ASR means were also greater in the dark, but relative measures of reflex modification (expressed as a proportion of the ASR baseline) were constant across time of day save for a slight compressive nonlinearity. The outcome for difference scores indicated that those neural mechanisms responsible for ASR elicitation and those responsible for ASR modification by external stimuli are both controlled in part by time of day, and the outcome for the relative response scores indicated further that the sensitivity of these separate reflex control mechanisms to the circadian process must be about equal.
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Chabot, C. C., & Taylor, D. H. (1992a). Circadian modulation of the rat acoustic startle response. Behavioral Neuroscience, 106, 846–852.
Chabot, C. C., & Taylor, D. H. (1992b). Daily rhythmicity of the rat acoustic startle response. Physiology & Behavior, 51, 885–889.
Davis, M. (1974). Signal-to-noise ratio as a predictor of startle amplitude and habituation in the rat. Journal of Comparative & Physiological Psychology, 86, 812–825.
Davis, M., & Sollberger, A. (1971). Twenty-four hour periodicity of the startle response in rats. Psychonomic Science, 25, 37–39.
Gerrard, R. L., & Ison, J. R. (1990). Spectral frequency and the modulation of the acoustic startle reflex by background noise. Journal of Experimental Psychology: Animal Behavior Processes, 16, 106–112.
Hoffman, H. S., & Ison, J. R. (1980). Reflex modification in the domain of startle: I. Some empirical findings and their implications for how the nervous system processes sensory input. Psychological Review, 87, 175–189.
Hoffman, H. S., Marsh, R. R., & Stein, N. (1969). Persistence of background acoustic stimulation in controlling startle. Journal of Comparative & Physiological Psychology, 68, 280–283.
Hoffman, H. S., & Searle, J. L. (1965). Acoustic variables in the modification of the startle reaction in the rat. Journal of Comparative & Physiological Psychology, 60, 53–58.
Hoffman, H. S., & Wible, B. L. (1970). Role of weak signals in acoustic startle. Journal of the Acoustical Society of America, 47, 489–497.
Horlington, M. (1970). Startle response circadian rhythm in rats: Lack of correlation with motor activity. Physiology & Behavior, 5, 49–53.
Ison, J. R., & Hammond, G. R. (1971). Modification of the startle reflex in the rat by changes in the auditory and visual environments. Journal of Comparative & Physiological Psychology, 75, 435–452.
Ison, J. R., McAdam, D. W., & Hammond, G. R. (1973). Latency and amplitude changes in the acoustic startle reaction produced by variation in auditory prestimulation. Physiology & Behavior, 10, 1035–1039.
Rusek, B. (1981). Vertebrate behavioral rhythms. In J. Aschoff (Ed.), Handbook of behavioral neurobiology: Vol. 4. Biological rhythms (pp. 183–213). New York: Plenum.
Sollberger, A., & Davis, M. (1972). Diurnal rhythm of the startle response: A statistical analysis. Journal of Interdisciplinary Cycle Research, 3, 313–325.
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This research was supported by USPHS Research Grant AG09524 and a Center Support Grant to the Center for Visual Science at the University of Rochester, EY01319.
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Ison, J.R., Foss, J.A. Coordinate diurnal variation in the strength of startle elicitation and of startle modification in the rat. Psychobiology 25, 158–162 (1997). https://doi.org/10.3758/BF03331922
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DOI: https://doi.org/10.3758/BF03331922