Cross-familiarisation conditioned taste aversion procedure as a method to reveal stimulus resemblance between drugs: studies on the 5-HT1A agonist 8-OHDPAT

In the present study a cross-familiarisation conditioned taste aversion (CTA) paradigm was utilized to reveal stimulus resemblance between the selective 5-HT_1A agonist 8-OHDPAT and a variety of serotonergic and non-serotonergic drugs. In male mice, a 0.22 mg/kg dose of 8-OHDPAT was used as the reference compound inducing CTA. Dose-dependent effects of pre-exposure to 24 different test drugs on the magnitude of the 8-OHDPAT-induced CTA were tested as a measure for stimulus similarity between these test drugs and 8-OHDPAT (the reference compound). Pre-exposure to 8-OHDPAT itself, ipsapirone, buspirone, RU 24969, sertraline,d-amphetamine, LSD, metergoline and idazoxan effectively prevented the development of CTA induced by 8-OHDPAT. Pre-exposure to apomorphine, diazepam, SCH 23390, LiCl, spiperone, DOI, spiroxatrine, umespirone, pindolol,mCPP, haloperidol, MK 212, clonidine, quipazine and also 5-MeODMT was not effective in completely abolishing the CTA produced by 8-OHDPAT. It is concluded from these results that the relatively simple and fast cross-familiarisation taste aversion method is a suitable paradigm to study similarities in stimulus properties of different drugs.