Cork gnawing in the rat as a screening method for buspirone-like anxiolytics

✍ Scribed by Gerald T. Pollard; James L. Howard

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 533 KB
• Volume: 22
• Category: Article
• ISSN: 0272-4391
• DOI: 10.1002/ddr.430220208

✦ Synopsis

Male Long-Evans rats were individually allowed access to No. 11 corks for 30 min per day. After 30 sessions, the mean amount gnawed away, 0.1 0 g per session, was stable enough to allow drug testing; it reached asymptote at 0.03 g after 140 sessions. Drugs were injected PO 30 min before testing, except as noted. On the asymptotic baseline, the novel anxiolytic buspirone (8-32 mgikg) and its congener gepirone (8-32 mg/kg) produced large, doserelated increases in cork gnawing. The standard anxiolytics chlordiazepoxide (1 6-32 mg/ kg) and meprobamate (128 mgikg, 60 min pretreatment) and the new sedative zopiclone (4-32 mgikg) also produced substantial increases. Diazepam, oxazepam, and alprazolam produced marginal increases, and pentobarbital had no effect at behaviorally relevant doses. The non-anxiolytics d-amphetamine, chlorpromazine, acute imipramine, morphine (IP), and valproic acid either decreased or did not change cork gnawing. Phencyclidine (IP) and scopolamine produced marginal increases. Apomorphine (5 mgikg SC) produced intense stereotyped gnawing of cage mesh but abolished gnawing of cork. Cork gnawing is proposed as a simple, economical behavioral method to identify buspirone-like anxiolytics.