FIG. 4.

PACAP-elicited responses in fura-2 AM loaded cultured rat ORNs. A: ratiometric fluorescence increases from an ORN in response to 100 nM PACAP, 25 μM n-amyl acetate + 50 μM R-carvone (odor), and high K⁺ Ringer solution. Note the transient increase in Ca²⁺ elicited by PACAP. Breaks in the traces correspond to 15 min when images were not collected. B: representative trace from a rat ORN that responded to multiple applications of PACAP (100 nM). C: PACAP-elicited intracellular Ca²⁺ transient returns to basal levels in the maintained presence of PACAP. Data are from 2 different ORNs. D: fluorescence increases from 3 rat ORNs that responded to 100 nM PACAP in 0 Ca²⁺ + EGTA.