Fig. 4.

Inhibition of evoked ACh-induced nerve terminal potential by hexamethonium and low Ca²⁺ medium. Nerve growth cone was whole-cell current-clamped at resting membrane potential. Evoked ACh-induced nerve terminal potentials were elicited by stimulating soma at 0.1 Hz. Note that hexamethonium (a), but not atropine (b), inhibited these depolarizing potentials. c, Replacement of normal Ringer’s solution with high-Mg²⁺, low-Ca²⁺ Ringer’s solution reversibly inhibited the evoked ACh-induced nerve terminal potentials.