Biochemical compartmentation of fish tissues. Cholesterol in the brain and spinal cord.

The differential distribution of cholesterol in different regions of the brain in 9 nutritionally important fishes were compartmentalized biochemically. The cholesterol content which was higher in the spinal cord than in the 4 brain regions, varied individually and groupwise; the medulla oblongata and cerebrum contained the highest and lowest amounts, respectively. The piscivorous fishes contain more cholesterol than cat fishes and major carps. A direct relationship was observed between the course of evolution and the cholesterol content in different regions of the brain and spinal cord of the nine kinds of fish studied. The differential distribution of cholesterol content in various regions of the brain and spinal cord are discussed in relation to phylogeny, diet and activity of the fish. Phylogeny seems to influence the biochemical compartmentation of the fish brain in relation to its cholesterol content.