Nicotinic acetylcholine receptor α5 subunits modulate oxotremorine-induced salivation and tremor

Neuronal nicotinic acetylcholine receptors (nAChRs) are composed of 12 subunits (α2–α10 and β2–β4). α5 Subunits, expressed throughout the central nervous system (CNS) and the autonomic nervous system (ANS), possess unique pharmacological properties. The effects of oxotremorine (OXO) on autonomic functions and tremor were examined in mice lacking α5 nAChR subunits (α5-/-) and compared with those in wild-type (WT) control mice. The α5-/- mice showed significantly increased salivation and tremor responses to OXO. The hypothermia, bradycardia and defecation induced by OXO were of similar magnitudes in the two mouse strains. The enhanced OXO effects in α5-/- mice indicate inhibitory effects of α5 subunits in autonomic ganglia, and support the participation of these subunits in cholinergic transmission in autonomic ganglia. [Copyright &y& Elsevier]