Repeated DOI and SR 46349B treatments do not affect elevated plus-maze anxiety despite opposite effects on cortical 5-HT2A receptors.
We report the consequences of a 4-day treatment (b.i.d) with the 5-HT2A,2B,2C receptor agonist 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI, 1.5 mg/kg) or the selective 5-HT2A receptor antagonist trans-4-[(3Z)3-(2-dimethylaminoethyl)oxyimino-3-(2-fluorophe nyl)propen-1-yl]phenol hemifumarate (SR 46349B, 7.5 mg/kg) on (i) anxiety-related behaviour in an elevated plus-maze, and (ii) specific [3H]ketanserin binding at central 5-HT2A receptors, in Roman rats. Neither DOI nor SR 46349B pretreatment affected the behaviour in the open arms of the elevated plus-maze; however, DOI pretreatment promoted discrete changes in the closed arm entries. The Bmax value of [3H]ketanserin binding at cortical 5-HT2A receptors was decreased by repeated DOI pretreatment. Conversely, Bmax, but also KD, values were increased by SR 46349B pretreatment. Thus, changes at central 5-HT2A receptors may occur without there being changes in anxiety-related behaviour in the elevated plus-maze.
Chaouloff
F
F
Génétique du Stress, INSERM CJF 94-05 INRA, Institut Francois Magendie, Bordeaux, France. francis.chaouloff@bordeaux.inserm.fr
Kulikov
A
A
Mormède
P
P
D000662:Amphetamines / Q000494:pharmacology*; D000818:Animals; D001007:Anxiety / Q000188:drug therapy*; D001522:Behavior, Animal / Q000187:drug effects*; D001835:Body Weight / Q000187:drug effects; D002540:Cerebral Cortex / Q000187:drug effects; D005260:Female; D005464:Fluorobenzenes / Q000494:pharmacology*; D007650:Ketanserin / Q000378:metabolism / Q000627:therapeutic use; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D010636:Phenols / Q000494:pharmacology*; D051381:Rats; D044402:Receptor, Serotonin, 5-HT2A; D011985:Receptors, Serotonin / Q000187:drug effects*; D012702:Serotonin Antagonists / Q000494:pharmacology*; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*
D000662:Amphetamines; D005464:Fluorobenzenes; D010636:Phenols; D044402:Receptor, Serotonin, 5-HT2A; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; C076033:SR 46349B; D007650:Ketanserin; C015952:4-iodo-2,5-dimethoxyphenylisopropylamine