Raymond A. Allen

Isolated cilia in inner retinal neurons and in retinal pigment epithelium.

Isolated cilia have been studied in neurons of the inner nuclear and ganglion cell layers of human and guinea pig retinas and in human retinal pigment epithelial cells. No more than one cilium per given cell has been observed. In retinal pigment epithelium the cilium extends into an intercellular pocket. In the retinal neurons the cilia show a 9 + 0 filament pattern in the basal body and proximal segments. One filament becomes displaced centrally, and for the greater portion of the cilium there is an 8 + 1 pattern. In the distal portion the filaments become frayed and indistinct. The plasma membrane over the tip of the cilium appears darker and more indistinct.