Fig. 4.

(Upper panel) Confocal images showing c-Fos immunoreactive cell nuclei (green) or the nuclear marker 4',6-diamidino-2-phenylindole (DAPI) (blue) in RVLM of rats treated (as described in Materials and Methods) with (from left to right) intra-RVLM vehicle, 0.2 nmol PGE₂ pretreated 10 minutes earlier with vehicle (100 nl; n = 6), EP2 (2 nmol TG4-155; n = 5), EP3 (0.1 nmol L-798106; n = 7), or EP4 (2 nmol L-161982; n = 5) receptor blocker. Scale bar, 20 μm. Bar graphs represent the mean ± S.E.M. of data obtained from four to six coronal brain stem sections/animal (n = 5–7 rats/group) using one-way analysis of variance followed by Bonferroni comparison test. *P < 0.05 versus vehicle values; ^#P < 0.05 versus PGE₂.