Figure 4

Selective block of slower-conducting CAP components in the Suncus murinus vagus nerve. (Left) Selected traces of vagal CAP corresponding to white lines on contour plot (right). (Trace 10) CAP before IR application. (Trace 27) CAP after IR application for 8.5 seconds. The slowest sub-population (~0.4 m/s) is inhibited (arrow). (Trace 41) CAP after IR application for 15.5 seconds. Both the slowest (~0.4 m/s) and intermediate velocity populations (~0.6 m/s) are inhibited (arrows). (Trace 59) CAP after removal of IR light; all CAP components are present, indicating reversibility. (Right) Contour plot of CAP traces (electrical stimulation frequency, 2 Hz) illustrating progressive preferential block of slow components during IR application (red vertical bar; on, trace 11; off, trace 51). Conduction velocity (m/s) is plotted against trace number. A color bar denotes trace voltages. For analysis of data, see Figure S8.