Fig. 3.

Preparation for CMAP recordings.

(A) Introduction of anesthesia with isoflurane. (B) Urethane administration for terminal anesthesia. (C) Shaving. (D) Exposed buccal branch of the facial nerves indicated by white arrows. Black arrows indicate sutures for fixation of the excised skin. (E) Introduction of accessory ear bars. (F) A rat mounted on a stereotaxic apparatus. (G) Introduction of a rectal thermistor for feedback temperature control. (H) A reference electrode fixed on the skull indicated by white arrow heads. (I) A stimulation bipolar electrode hooked to the buccal branch of the facial nerves indicated by magenta arrow heads. Note that anodal and cathodal terminations should be connected to the proximal and distal parts of the nerves, respectively. (J) A small skin incision on the middle of the vibrissal rows C and D of the whisker pad, indicated by a red arrow head. A vibrissal alignment schema is superimposed on the whisker pad. (K) A recording microelectrode inserted into the whisker pad. (L) CMAP recording configuration for mice. The same recording, stimulating and reference electrodes are used. However, the mouthpiece and ear bars are replaced by ones specific to mice.