Müller Cells in the Healthy Retina
Müller cells (Figs. 1.17c, d, 2.1, 2.5, 2.9, 2.13, and 2.31) are radial glial cells that reside in a part of the adult CNS. As such, they share the basic bipolar morphology of radial glial cells (Figs. 1.1 and 1.4) and possess the complete set of principal glial cell processes/contact types (Fig. 1.3) (Reichenbach, 1989b). Originating from soma which generally is located in the inner nuclear layer (where the somata of all Müller cells may even constitute a sublayer) two stem processes extend into opposite directions. The outer stem process reaches to the subretinal space (i.e., the relict of the optic ventricle) into which it sends numerous microvilli. The inner stem process approaches the vitread surface of the neuroretina where it forms a so-called endfoot abutting the basal lamina between the vitreous body and the neuroretina (the “inner limiting membrane”, ILM).