1. The concentration of water, cerebroside (glycosphingoside), free and total cholesterol, total phospholipin, monoaminophospholipin (phosphoglyceride) and lecithin (phosphatidyl choUne) was determined in the brains of a series of vertebrates, including representatives of the cartilaginous and bony fishes, amphibians, reptiles birds and mammals. From these figures was calculated the concentration of ester cholesterol, sphingomyelin (phosphosphingoside) and kephalin.
2. The brains of each of the species contained a negligibly small concentration of cholesterol ester and, unlike the nervous system of certain invertebrates, the brains of all the species contained some cerebroside.
3. The concentration of each lipid in the brain was very similar for different individuals of the same species, but for various species within one class the mean concentration of many of the lipids differed greatly.
4. The mean concentration of total myelin lipid and that of each of the individual myelin lipids, i.e. cerebroside, cholesterol and sphingomyelin, was greater in the brains of the mammals than in the brains of the lower vertebrates.
- Copyright © 1952 The Company of Biologists Ltd.