Preclinical abuse liability assessment of ABT-126, an agonist at the α7 nicotinic acetylcholine receptor (nAChR)

Abstract

ABT-126 is a nicotinic acetylcholine receptor (nAChR) agonist that is selective for the α7 subtype of the receptor. nAChRs are thought to play a role in a variety of neurocognitive processes and have been a pharmacologic target for disorders with cognitive impairment, including schizophrenia and Alzheimer's disease. As part of the preclinical safety package for ABT-126, its potential for abuse was assessed. While the involvement of the α4β2 subtype of the nicotinic receptor in the addictive properties of nicotine has been demonstrated, the role of the α7 receptor has been studied much less extensively. A number of preclinical assays of abuse potential including open-field, drug discrimination and self-administration were employed in male rats. ABT-126 had modest effects on locomotor activity in the open-field assay. In nicotine and d-amphetamine drug discrimination assays, ABT-126 administration failed to produce appreciable d-amphetamine-like or nicotine-like responding, suggesting that its interoceptive effects are distinct from those of these drugs of abuse. In rats trained to self-administer cocaine, substitution with ABT-126 was similar to substitution with saline, indicating that it lacks reinforcing effects. No evidence of physical dependence was noted following subchronic administration. Overall, these data suggest that ABT-126 has a low potential for abuse. Together with other literature on this drug class, it appears that drugs that selectively activate α7 nAChRs are not likely to result in abuse or dependence.