Figure 7. ChAT expression in the arteries and 4-DAMP-sensitity of the excitatory junction potential (EJP) in the SMA.
A–I, micrographs showing that ChAT-immunoreactive fibres (bright red) were present in basilar artery (BA) (A), anterior-inferior-cerebellar artery (AICA) (D) and SMA (G). Note that ChAT-labelled nerve fibres and varicosities form a sparse plexus (arrows). When the vessels were incubated with a medium containing blocking peptide-adsorbed ChAT antibodies, negligible labelling was noted in all the vessels tested (B, E and H). When primary antibody was replaced by BSA-PBS, no labelling was observed (C, F and I). Scale bars in micrometres. J, traces showing EJPs recorded from two cells having low and high RP, respectively, in the SMA. The M3 receptor-selective antagonist 4-DAMP, significantly attenuated the EJP in the cell that had a high RP cell (bottom traces) but not in the other (upper traces). Each trace was an average of 5 sweeps. The stimulus artifact was truncated for clarity.