ABSTRACT
For many years, neurophysiologists have investigated the activity of the brain by examining the firing patterns of single neurons one at a time while stimuli were presented or the animal performed trained tasks. Depending upon the size of the electrode employed, the activity of several neurons was sometimes recorded simultaneously and the resultant record separated into single-unit activity by hardware devices or computer programs. Although many scientists would have liked to record from many neurons simultaneously, the electrode technology and computer processing were not readily available. A number of electrode technologies have been and
are being developed (see reference 1 for an earlier review), and low-cost, highperformance computers are now available. The area of multiple simultaneous single neuron recording will be the wave of the future. In this first chapter, we review the microelectrodes and drives used for
in vivo
recording from the central nervous system.
