A 12-fold microelectrode for recording from vertically aligned cortical neurones.

Twelve glass-coated wire microelectrodes of different lengths permit one to record along a vertical cortical neuron when the penetration angle is 45 degrees. Single units can be isolated at about half of the electrodes. Simultaneous events and spatial activity distributions can be studied; the method saves time, economizes on the use of experimental animals, and is advantageous for teaching.