Figure 1.

PAR-APs and thrombin activate cultured myenteric neurons. Representative traces of voltage sensitive dye recordings showing neuronal responses to a 2 s spritz application (indicated by the horizontal gray bar) of PAR1-AP, PAR2-AP, PAR4-AP, and thrombin. Recordings were made in four 2 s long recording periods with 5–6 s intervals in between (indicated by the symbol between the traces). Every peak represents an action potential. (A) Representative traces from cultured human myenteric neurons to human specific PAR-APs and thrombin show comparable responses to PAR1-AP and thrombin but no response to PAR2-AP and a minor response to PAR4-AP. (B) Guinea pig cultured myenteric neurons fire action potentials in response to PAR1-AP, PAR2-AP, PAR4-AP, and thrombin; the PAR4 response is rather moderate.