Membrane currents in a developing parasympathetic ganglion.

Abstract It is reported that chick embryo ciliary ganglion neurons that have just terminated their migration and are in the process of forming a ganglion express several properties underlying membrane excitability. Evidence is presented which suggests that these cells possess voltage-dependent sodium, potassium, and calcium currents as well as a calcium-activated potassium current. These currents resemble those previously described in the more mature ciliary ganglion (Bader, C. R., Bertrand, D., and Kato, A. C. (1982). Dev. Biol. 94, 131–141) but may differ in their density per unit membrane surface. For example, the density per unit surface of the voltage dependent sodium current in younger neurons appears to be 5 to 10 times smaller than in more mature neurons.