Evaluation of Microelectrodes Chronically Implanted on the Retina

Abstract

The methods available for the recording of both gross and unitary action potentials from the mammalian retina have been improved significantly in recent years (Werblin & Dowling, 1969; Dawson, Zimmerman & Houde, 1974). Both identification of cells producing unitary responses and safety of contact lenses have been improved. However, unit recording methods still require extensive surgery with anesthesia and/or neuromuscular blocking. Unit recording durations are limited under these circumstances (Rodieck, 1967; Kuffler, 1953). Corneal contact lenses provide the opportunity of recording potentials from unanesthetized animals and humans but such lenses may not be left in place indefinitely while their replacement on subsequent days may contribute to data variability (Lawwill, 1969). Experimentation with chronic electrode implantations upon the retinal surface has probably been impeded by the well known toxic response of the eye to foreign materials.