Rivanicline hemioxalate, also known as RJR-2403 hemioxalate or (E)-Metanicotine hemioxalate, is a chemical compound acting as a neuronal nicotinic receptor agonist with pronounced selectivity for the alpha4beta2 receptor subtype, showing over 1,000-fold greater selectivity for this subtype (Ki=26 nM) compared to alpha7 receptors (Ki=3.6 uM). Its in vitro studies demonstrate no significant activation of nAChRs in PC12 cells, muscle type nAChRs, or muscarinic receptors at concentrations up to 1 mM. Furthermore, Rivanicline displayed less than one-tenth the potency of nicotine in inducing ileum contraction, with substantially lower efficacy, and failed to antagonize nicotine-induced stimulation of muscle or ganglionic nAChR functions, with an IC50 value greater than 1 mM. Chronic exposure to Rivanicline at 10 microM led to up-regulation of high-affinity nAChRs in M10 cells, mimicking effects observed with nicotine. In vivo studies revealed that Rivanicline significantly reversed scopolamine-induced amnesia and improved working and reference memory in a rat model, while being 15 to 30 times less potent than nicotine in affecting body temperature, respiration, and other physiological responses. Metanicitone s potency was approximately five times lower than nicotine in tail-flick tests following subcutaneous administration, yet slightly more potent upon central administration.