Fig. 2.

Modulation of chick ciliary ganglion presynaptic calcium current by neurotransmitter. The degree of current recruitment was determined using a double-trial protocol (see Materials and Methods) before, during, and after a puff of transmitter onto the terminal. Each panel shows before (left column) and during (right column) transmitter application in a single calyx nerve terminal. GTP (0.1 mm) was included in the internal solution in all experiments except in panel 1.Panel 1, Adenosine (10 μm) in the absence of internal GTP. Panel 2, Adenosine (10 μm) treatment. Panel 3, Treatment with a mix of substance P (0.5 μm), bradykinin (1 μm), neuropeptide Y (0.1 μm), and BRL52537 (1 μm). Panel 4, Treatment with a mix of noradrenaline (100 μm) and somatostatin (10 μm). −pp, Without prepulse; +pp, with prepulse.