Non-muscarinic effects of scopolamine on N1E-115 neuroblastoma cells

Membrane effects of scopolamine on N1E-115 neuroblastoma cells were studied using intracellular recording techniques. Scopolamine in concentrations of 50 nM-1 microM induced a depolarization together with a decreased cell input resistance. This response had a reversal potential at +10 to +20 mV in a medium with normal sodium concentration (146.5 mM), and a reversal potential around -10 mV when the sodium concentration in the medium was lowered to 80 mM. The scopolamine-induced depolarization could not be blocked by carbachol (100 microM), and had a reversal potential at +10 to +20 mV. The simplest explanation of the results obtained is that scopolamine increases the membrane permeability for sodium and potassium, in a manner which is not related to muscarinic cholinergic receptors.