A method to record changes in local neuronal discharge in response to infusion of small drug quantities in awake monkeys.

A newly designed combination microelectrode-injection system is described which can be used to record electrophysiological responses of individual neurons in the primate brain to local administration of small quantities of drugs or other compounds. The assembly of the system is simple, and the materials used are inexpensive. The system consists of a standard tungsten microelectrode alongside fused silica tubing within a polyimide sleeve. The major advantage of this device is the ability to record with excellent quality, changes in the activity of single cells in vivo within 50-100 microm of the location of drug injections.