Chemical and Ultrastructural Comparison of Synthetic and Pathologic Membrane System

Characteristic membranous bodies have been previously reported in the cytoplasm of the cerebral neurons in Tay-Sachs disease (1) (Fig. 1). Subsequently (2) these lamellated particles were isolated from homogenized autopsy tissue by differential and density gradient centrifugation and subjected to extensive chemical analysis. The membranous cytoplasmic bodies (MCB) were found to consist of about 50 per cent (dry weight) gangliosides and could account for the accumulation of this complex sphingolipid which characterizes this lipid-storage disease. The appearance and composition of the MCB suggested: (1) that they might arise from an alteration of cytoplasmic organelles, or (2) that they were formed spontaneously by interaction of the component lipids in a fashion analogous to myelin figure formation (3). Chemicals approximating the known composition of the MCB were combined in proper proportion in vitro as a test of this latter hypothesis. The resultant aggregates were examined with light and electron microscopy.