Age-dependent changes of gap detection in the Mongolian gerbil (Meriones unguiculatus).

Gap detection using broadband noise was characterized in a group of young gerbils from the breeding colony of the University of Regensburg (RB gerbils), old RB gerbils, and old gerbils from the breeding colony of the University of South Carolina (SC gerbils). Data from old RB and old SC gerbils were not significantly different and were subsequently combined for a comparison with data from the group of young RB gerbils. Level dependence of gap-detection thresholds in young and old domesticated gerbils resembled the typical mammalian pattern of level dependence. Gap-detection thresholds of old gerbils were significantly elevated at 30 dB SL and 50 dB SPL as compared with young gerbils. Compared with young gerbils tested at 30 dB SL and 50 dB SPL, the distribution of gap-detection thresholds in old gerbils was broader with a spread to higher gap-detection thresholds. Some old animals retained excellent temporal resolution, while some showed impaired gap detection. The gap-detection data collected in young and old gerbils resemble previously published data from humans of different age and confirm that gerbils are a useful model to study age-dependent changes in temporal processing.