N‐benzhydryl quinuclidine compounds are a potent and Src kinase‐independent inhibitor of NALCN channels

BACKGROUND AND PURPOSE: leak, GPCR-activated channel that regulates the resting membrane potential and neuronal excitability. Despite numerous possible roles for NALCN in both normal physiology and disease processes, lack of specific blockers hampers further investigation. EXPERIMENTAL APPROACH: The effect of N-benzhydryl quinuclidine compounds on NALCN channels was demonstrated using whole-cell patch-clamp recordings in HEK293T cells overexpressing NALCN and acutely isolated nigral dopaminergic neurons that express NALCN endogenously. Src kinase activity was measured using a Src kinase assay kit, and voltage and current-clamp recordings from nigral dopaminergic neurons were used to measure NALCN currents and membrane potentials. KEY RESULTS: leak currents and hyperpolarized the membrane potential in native midbrain dopaminergic neurons that express NALCN endogenously. CONCLUSION AND IMPLICATIONS: These findings suggest that N-benzhydryl quinuclidine compounds have a pharmacological potential to directly inhibit NALCN channels and could be a useful tool to investigate functions of NALCN channels.