Fine structure of cilia in rat cerebral cortex

Summary Cilia have been demonstrated on granular neurons and astroglial cells in the fascia dentata, a part of the hippocampal region, in the rat. Every granular cell seems to possess one cilium, which shows an 8+1 pattern in the greater part of its length. This 8+1 pattern is shown to result from the displacement of one peripheral doublet of a 9+0 cilium into the middle of the cilium. The neuronal cilia have a two-centriole basal organization, and fine rootlets radiate from the basal body proper into the cytoplasm. The possible function and significance of these cilia are discussed on the basis of earlier literature.This study was supported in part by Grant NB 02215 of The National Institute of Neurological Diseases and Blindness, U.S. Public Health Service, in part by The Norwegian Research Council for Science and the Humanities. This aid is gratefully acknowledged. I am greatly indebted to Dr. Th. Blackstad for encouragement and advice during this study, to Mrs. J. L. Vaaland, Mr. B. V. Johansen and Mr. E. Risnes for technical assistance, and to Dr. B. Afzelius for valuable discussions.