Electrophysiological characteristics of enteric neurons from immortomouse

Abstract

Enteric neurons play a major role in gastrointestinal peristalsis. Isolating individual neurons has proven difficult in the mouse due to their accessibility. Here we characterized the properties of post-natal enteric neuron cell line (IM-PEN) from the H-2Kb-tsA58 immortomouse. IM-PEN cells stained positively for pan neuronal markers. In whole cell voltage clamp, depolarization from Vh-60 mV elicited outward currents with slow deactivating tail currents that were blocked by niflumic acid and low chloride solution (n=6). A volume-regulated anion current was elicited by hypo-osmotic solution and inhibited by 10μM DCPIB (n=6). In current clamp, the resting membrane potential was −24.7 ± 4.7mV (n=6) and action potentials could not be elicited upon current injection from −60 mV. Sodium currents of −46 ±11pA at −10mV were recorded in 4/26 cells from Vh −80 mV but no calcium currents (n=9) were observed. The mRNA for ion channels including sodium, potassium, and TRPV1 were detected by RT-PCR. High levels of TRPV1 transcription correlated to immunohistochemical localization of TRPV1 in intracellular vesicles. A high chloride conductance resulting in a depolarized membrane potential is a characteristic of immature neurons. IM-PEN may represent immature enteric neurons and could be useful to examine the effect of factors required for the development of mature enteric neurons. Supported by NIH DA024009 and T32DA007027