Fig. 1.

(A) Optical recording of neural responses to N.IX stimulation in an E12 mouse en bloc preparation. The recording was made with the ventral side up and with a magnification of x25. The cut end of the N.IX was electrically stimulated with a depolarizing pulse (8 μA/5 msec) using a suction electrode. The relative position of the image of the preparation is drawn on the recording, and signals detected on the stimulated side are shown. The direction of the arrow in the lower right of the figure indicates an increase in transmitted light intensity (a decrease in dye absorption), and the length of the arrow represents the stated value of the fractional change. (B) Enlarged traces of optical signals detected in positions 1–4 in A. The signals detected in the rostro-medial region (gray shadow: positions 1 and 2) consisted of a fast spike-like signal (indicated by arrowheads), whereas those detected in the lateral region (positions 3 and 4) exhibited two components: a fast spike-like signal (indicated by arrowheads) and a long-lasting slow signal (indicated by asterisks). In this and other recordings, signal averaging of two trials was performed offline. N.IX, glossopharyngeal nerve; N.X, vagus nerve.