THE CONTRIBUTION OF GLIAL-CELLS TO SPONTANEOUS AND EVOKED-POTENTIALS

The mechanism by which brain cells generate alpha and other rhythms re mains obscure, and the possible participation of glial cells in the pr ocess continues to be debated. We will present data obtained from free ly moving rats in which flashes produced by a light emitting diode imp lanted under the skin of the scalp evoke retinal and cortical response s recorded through electrodes implanted behind the eye and over visual cortex. In the retina, which is a brain-like structure isolated in th e periphery during embryology, the b-wave evoked response is thought t o be produced by the Muller glial cells as they maintain potassium ion homeostasis in the extracellular space during the synaptic events ini tiated by rod and cone activation. We will report on the results of a search in this retinal analogue of the brain for spontaneous activity in the EEG spectrum. (C) 1997 Elsevier Science B.V.