Gap detection methods for assessing salicylate-induced tinnitus and hyperacusis in rats.
OBJECTIVE
A variety of options for behavioral assessment of tinnitus in laboratory animals are available to researchers today. These options are briefly reviewed, followed by data suggesting that gap detection procedures might be used to efficiently measure acute, salicylate-induced tinnitus and possibly hyperacusis in rats.


METHODS
Fischer Brown Norway rats (n = 10) were given intraperitoneal injections of 350 mg/kg sodium salicylate on 2 consecutive days, and the effects on gap detection were observed across 9 different frequency bands. Pretest, posttest, and washout data were collected. An additional 4 rats were each given 4 different doses of sodium salicylate (0, 150, 250, and 300 mg/kg), and gap detection and prepulse inhibition were measured.


RESULTS
Significant gap detection deficits were observed from pre- to posttest that were consistent with tinnitus. Consistent gap detection deficits were found using broadband noise backgrounds, while significant improvements in responding to frequency-specific test bands were found. Similar effects were repeated in the dose response portion of the study.


CONCLUSIONS
Gap detection procedures efficiently measured salicylate-induced changes in behavior that were consistent with the presence of tinnitus. In addition, the reliable, stronger responses at many frequencies after salicylate injections suggest the possibility of measuring a hyperacusis-like phenomenon using these methods.
Turner
Jeremy G
JG
Department of Surgery/Otolaryngology Head and Neck Surgery, Southern Illinois University School of Medicine, Springfield, IL 62794-9629, USA. jturner@siumed.edu
Parrish
Jennifer
J
D000161:Acoustic Stimulation; D000818:Animals; D001288:Attention / Q000187:drug effects; D012001:Hyperacusis / Q000139:chemically induced*; D007274:Injections, Intraperitoneal; D051381:Rats; D011914:Rats, Inbred BN; D013216:Reflex, Startle / Q000187:drug effects; D012980:Sodium Salicylate / Q000633:toxicity*; D013018:Sound Spectrography; D014012:Tinnitus / Q000139:chemically induced* / Q000175:diagnosis*
D012980:Sodium Salicylate