Respiratory activity variations induced in groups of LD 12:12 synchronized Sprague-Dawley rats by a 100 dB white noise emitted at 12-h intervals
Stupfel, M.; Molin, D.; Thierry, H.; Busnel, M.C.
Chronobiologia 7(3): 337-342
1980
ISSN/ISBN: 0390-0037 PMID: 6778676 Document Number: 159733
A white noise is emitted during 2 h, either in the middle of the scotoperiod (activity period) or of the photoperiod (rest period), on grouped specific pathogen free (SPF) male Sprague-Dawley rats, LD 12:12 synchronized by light (L = 6 h = 150 lux). Continuous measurements of VCO2, taken as an index of respiratory activity shows: 1. a short increase both after the beginning and the end of the stimulus, with slight time length differences between young and older rats; 2. a slight (2-3%) continued increase during the photoperiod and a high decrease (13%) during the scotoperiod. These VCO2 variations obtained during and after the white noise emission correspond to measurements of activity displacement and observations of behavior performed on a small sample of rats.