Figure 3.

Fluorimetric measurements. Measurement of changes of Ca²⁺-levels in separated ROIs in response to high K⁺ and amino acids in the rhinophore ganglion (stimulus duration was one minute in each case). A: Application of artificial sea water with high K⁺. Responses were stable and could be reproduced after wash-out. B: Ca²⁺-responses of ROIS of three different animals to the stimulation with 2 mM alanine (ALA). An elevation as well as a decrease of the Ca²⁺-levels were found. C: Responses in two regions to stimulation with different amino acids (2 mM). Arginine (ARG) and glutamine (GLN) did not induce a response in one region (upper trace), whereas glycine (GLY) and valine (VAL) did evoke a response. Phenylalanine (PHE) did not induce any response. A second region (lower trace) responded to all amino acids except PHE.