Figure 1. Experimental set-up for single-fiber recording. aCSF = artificial cerebrospinal fluid; HEAT = heating element; TEMP = automated temperature controller and monitor; STIM = nerve stimulator; AMP = preamplifier and amplifier circuit connected to the computer data acquisition system. An actual example of single-fiber activity can be seen on the monitor. It was recorded from two unmyelinated dorsal root axons (conduction velocity = 1.48 m/s and 1.02 m/s). The stimulus artifact is seen at the beginning of the trace. Time and voltage calibrations are shown in the right corner.