The effects of intracranial injection of three β3-adrenoceptor agonists, sodium-4-[-2[-2-hydroxy-2-(-3-chloro-phenyl)ethylamino] propyl]phenoxyacetate (BRL 37344), 2-hydroxy-5(2-((2-hydroxy-3-(4-((1-methyl-4-trifluoromethyl) 1H-imidazole-2-yl)-phenoxy)propyl)amino)ethoxy)-benzamide monomethane sulfonate) (±)-CGP12177A) and the pro-drug RS-N-(7-carbethoxymethoxyl 1,2,3,4-tetrahydronaphth-2-yl)-2 hydroxy 2-(3-chlorophenyl)ethanamine (SR58611A), were examined on reinforcement of memory in day-old chicks. BRL37344 and CGP12177 facilitated memory, whereas SR58611A had no effect. The dose-response relationships of the β3-adrenoceptor agonists were challenged with the selective β3-adrenoceptor antagonist 3-(2-ethylphenoxy)-1-[(1S)-1,2,3,4-tetrahydronapth-1-ylamino]-2S-2-propanol oxalate (SR59230A) or the β2-adrenoceptor antagonist (-)propranolol. BRL 37344 appeared to act predominantly at β3-adrenoceptors at low doses and at β2-adrenoceptors at higher doses. Facilitation of labile into long-term storage by β3-adrenoceptor agonists appears to be a class action of these drugs.
- Memory, labile
- Passive avoidance learning