Microelectrode implantation technique for use in the awake and unrestrained cat

A technique is described for repeated implantation of movable microelectrodes through a large cranial opening into the cerebellum of an awake cat. Accurate implantation of electrodes through a regrown dura, over a period of months is accomplished by using a hand drawn map of the cortical surface and skull reference marks in conjunction with a dissecting microscope and calibrated eye piece. An animal preparation with a large cranial opening permits greater experimental flexibility and the simultaneous use of several microelectrodes. Silastic elastomers are employed in this technique to facilitate reimplantation, prevent herniation of the cortical surface and provide for increased recording stability. The technique has been used successfully for recording the restrained as well as freely moving animals over a period of 6 months.