Phantom auditory sensation in rats: an animal model for tinnitus.
In order to measure tinnitus induced by sodium salicylate injections, 84 pigmented rats, distributed among 14 groups in five experiments, were used in a conditioned suppression paradigm. In Experiment 1, all groups were trained with a conditioned stimulus (CS) consisting of the offset of a continuous background noise. One group began salicylate injections before Pavlovian training, a second group started injections after training, and a control group received daily saline injections. Resistance to extinction was profound when injections started before training, but minimal when initiated after training, which suggests that salicylate-induced effects acquired differential conditioned value. In Experiment 2 we mimicked the salicylate treatments by substituting a 7 kHz tone in place of respective injections, resulting in effects equivalent to salicylate-induced behavior. In a third experiment we included a 3 kHz CS, and again replicated the salicylate findings. In Experiment 4 we decreased the motivational level, and the sequential relation between salicylate-induced effects and suppression training was retained. Finally, no salicylate effects emerged when the visual modality was used. These findings support the demonstration of phantom auditory sensations in animals.
Jastreboff
P J
PJ
Department of Surgery, Yale University School of Medicine, New Haven, Connecticut 06510.
Brennan
J F
JF
Coleman
J K
JK
Sasaki
C T
CT
D000818:Animals; D001288:Attention / Q000502:physiology; D001306:Auditory Pathways / Q000502:physiology; D001307:Auditory Perception / Q000502:physiology*; D003214:Conditioning, Classical / Q000502:physiology*; D005108:Extinction, Psychological / Q000502:physiology; D008297:Male; D009042:Motivation / Q000502:physiology; D051381:Rats; D012980:Sodium Salicylate / Q000494:pharmacology; D014012:Tinnitus / Q000139:chemically induced / Q000503:physiopathology*; D000159:Vestibulocochlear Nerve / Q000503:physiopathology
D012980:Sodium Salicylate