Fig. 7.

Depolarization stimulates sympathetic neuron PACAP release. SCG neurons were dissociated enzymatically and plated at an initial density of 1.5 × 10⁴ cells/cm²onto 16 mm (2 cm²) dishes. On day 9 of culture, the sympathetic neurons were incubated in 500 μl of defined medium containing 40 mm NaCl (control, ▪) or 40 mmKCl (high potassium, •) for 96 hr. Every 24 hr, the conditioned medium was collected for PACAP38 radioimmunoassay, and replaced with fresh medium containing NaCl or KCl. Data represent the mean cumulative femtomoles of PACAP38 immunoreactivity per 10⁴ cells ± SEM (n = 3–6 samples). Error bars are within the symbols.