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Show J. Clin. Neuro-ophthalmol. 2: 215-216, 1982. The visual cortex is primarily located on the medial aspect of the occipitdl lobe. Only 3% is found on the posterolateral surface. The occipital lobe rests on the tentorium cerebelli .md is therefore above the cerebellum (CER). The rostral boundary is the parieto-occipital sulcus (white arrowheads). Anterior to this sulcus is the precuneus (P), the caudal portion of the parietal lobe. The calcarine fissure (CAL) divides the occipital lobe into the cuneus (C) above and lingual gyri (L) below. These are regarded as the upper and lower banks of the visual cortex. The calcarine and the parieto-occipital sulcus join anteriorly in a Yshaped configuration. The anterior end of the calcarine varies and it may be close to the colliculi, pulvinar and to the splenium of the corpus callosum (5). The visual cortex is characterized by having a white line or stria that can be seen in sections of the cortex with the naked eye. This is the white stria of Gennari (W5G), and it has given the pri- From the Department of Ophthalmology, Bascom Palmer Eye Institute. University of Miami School of Medicine (NBB), and Department of Anatomy, University of Miami School of Medicine CRGC), Miami, Florida. September 1982 Neuro-anatomical Feature Photo NORMA BOSCHETTI BARTON, MD., PhD. RONALD G. CLARK, PhD. mary visual cortex the name "area striata." The specimen illustrated was fixed in formalin. The white stria of Gennari is even more visible in a freshly cut brain. It is said to contain one-tenth of the total number of cells in the cerebral cortex (Gray, Wolff). When one sees microscopic sections of the human cortex, six layers are identified: I) molecular or plexiform, II) external granular, JII) external pyramidal, IV) internal granular, V) internal pyramidal, and VI) multiform or fusiform layer. With the Weigert myelin stain, dense bands are seen in layers IV (external band of Baillarger) and V (internal band of Baillarger). By comparison with other areas of the brain, the striate cortex is relatively thin; the granular layer, (IV) however, is very thick. This thickened outer band of BaiIJarger (IV) which is visible to the naked eye as the stria of Gennari is seen only in the calcarine cortex. Even neuro-ophthalmology has anatomical uniqueness' Write for reprints to: Norma Boschetti Barton, MD., Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami School of Medicine, P.O. Box 016880, Miami, Florida 33101. 215 Neuro-anatomical Feature Photo Journal of Clinical Neuro-ophthaJmoJogy |