The selective nicotinic acetylcholine receptor alpha 7 agonist JN403 is active in animal models of cognition, sensory gating, epilepsy and pain

Several lines of evidence suggest that the nicotinic acetylcholine receptor alpha 7 (nAChR alpha 7) is involved in central nervous system disorders like schizophrenia and Alzheimer's disease as well as in inflammatory disorders like sepsis and pancreatitis. The present article describes the in vivo effects of JN403, a compound recently characterized to be a potent and selective partial nAChR alpha 7 agonist. JN403 rapidly penetrates into the brain after i.v.. and after p.o. administration in mice and rats. In the social recognition test in mice JN403 facilitates learning/memory performance over a broad dose range. JN403 shows anxiolytic-like properties in the social exploration model in rats and the effects are retained after a 6 h pre-treatment period and after subchronic administration. The effect on sensory inhibition was investigated in DBA/2 mice, a strain with reduced sensory inhibition under standard experimental conditions. Systemic administration of JN403 restores sensory gating in DBA/2 mice. both in anaesthetized and awake animals. Furthermore, JN403 shows anticonvulsant potential in the audiogenic seizure paradigm in DBA/2 mice. In the two models of permanent pain tested, JN403 produces a significant reversal of mechanical hyperalgesia. The onset was fast and the duration lasted for about 6 h. Altogether, the present set of data suggests that nAChR alpha 7 agonists, like JN403 may be beneficial for improving learning/memory performance, restoring sensory gating deficits, and alleviating pain, epileptic seizures and conditions of anxiety. (C) 2008 Elsevier Ltd. All rights reserved.