Fig. 6.

PACAP increases excitability in Ba²⁺-treated cells. Excitability curves are summarized for 4 cells bathed first in control solution, then exposed to a solution containing 1 mM Ba²⁺, and finally bathed in a solution containing 1 mM Ba²⁺ + 10 nM PACAP. Values are means ± SE of number of action potentials generated by a 1-s depolarizing current pulse at multiple stimulus intensities, with lines fit with a linear regression. Averaged slopes were 3.50 ± 0.74 in control solution, 11.00 ± 7.02 during exposure to 1 mM Ba²⁺ alone, and 49.50 ± 14.98 during exposure to 1 mM Ba²⁺ + 10 nM PACAP. Slopes were significantly greater for cells exposed to Ba²⁺ alone and Ba²⁺ + PACAP than for the same cells exposed only to control solution. Slope was significantly greater for Ba²⁺ + PACAP than Ba²⁺ alone.