Constraints on decay of environmental sound memory in adult rats.
When adult rats are pretreated with a 48-h-long 'repetitive nonreinforced sound exposure', performance in two-sound discriminative operant conditioning transiently improves. We have already proven that this 'sound exposure-enhanced discrimination' is dependent upon enhancement of the perceptual capacity of the auditory cortex. This study investigated principles governing decay of sound exposure-enhanced discrimination decay. Sound exposure-enhanced discrimination disappeared within approximately 72 h if animals were deprived of environmental sounds after sound exposure, and that shortened to less than approximately 60 h if they were exposed to environmental sounds in the animal room. Sound-deprivation itself exerted no clear effects. These findings suggest that the memory of a passively exposed behaviorally irrelevant sound signal does not merely pass along the intrinsic lifetime but also gets deteriorated by other incoming signals.
Sakai
Masashi
M
Department of Physiology, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, Yamanashi, Japan. msakai@yamanashi.ac.jp
D000161:Acoustic Stimulation / Q000379:methods; D000818:Animals; D001522:Behavior, Animal; D003216:Conditioning, Operant / Q000502:physiology; D004193:Discrimination Learning / Q000502:physiology*; D004777:Environment; D008144:Loudness Perception / Q000502:physiology*; D008297:Male; D008568:Memory / Q000502:physiology*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D013016:Sound; D013997:Time Factors