Pro-cognitive activity in rats of 3-furan-2-yl-N-p-tolyl-acrylamide, a positive allosteric modulator of the [alpha]7 nicotinic acetylcholine receptor

• Published in: British journal of pharmacology 2015-11, Vol.172 (21), p.5123
• Main Authors: Potasiewicz, A, Kos, T, Ravazzini, F, Puia, G, Arias, H R, Popik, P, Nikiforuk, A
• Format: Article
• Language: English
• ISSN: 0007-1188; 1476-5381
• DOI: 10.1111/bph.13277

Background and Purpose [alpha]7 nicotinic acetylcholine receptors ([alpha]7 nAChRs) may represent useful targets for cognitive improvement. The aim of this study is to compare the pro-cognitive activity of selective [alpha]7-nAChR ligands, including the partial agonists, DMXBA and A-582941, as well as the positive allosteric modulator, 3-furan-2-yl-N-p-tolyl-acrylamide (PAM-2). Experimental Approach The attentional set-shifting task (ASST) and the novel object recognition task (NORT) in rats, were used to evaluate the pro-cognitive activity of each ligand [i.e., PAM-2 (0.5, 1.0, and 2.0 mg·kg-1), DMXBA and A-582941 (0.3 and 1.0 mg·kg-1)], in the absence and presence of methyllycaconitine (MLA), a selective competitive antagonist. To determine potential drug interactions, an inactive dose of PAM-2 (0.5 mg·kg-1) was co-injected with inactive doses of either agonist - DMXBA: 0.1 (NORT); 0.3 mg·kg-1 (ASST) or A-582941: 0.1 mg·kg-1. Key Results PAM-2, DMXBA, and A-582941 improved cognition in a MLA-dependent manner, indicating that the observed activities are mediated by [alpha]7 nAChRs. Interestingly, the co-injection of inactive doses of PAM-2 and DMXBA or A-582941 also improved cognition, suggesting drug interactions. Moreover, PAM-2 reversed the scopolamine-induced NORT deficit. The electrophysiological results also support the view that PAM-2 potentiates the [alpha]7 nAChR currents elicited by a fixed concentration (3 µM) of DMXBA with apparent EC50 = 34 ± 3 µM and Emax = 225 ± 5 %. Conclusions and Implications Our results support the view that [alpha]7 nAChRs are involved in cognition processes and that PAM-2 is a novel promising candidate for the treatment of cognitive disorders.