[Multiple forms of brain cholinesterase in phylogenesis and ontogenesis of vertebrates].

Multiple forms of the brain cholinesterase have been investigated by means of the original technique based on the extraction, ammonium sulphate salting out and gel filtration on Sephadex G-200. It was shown that the number of multiple forms increases in phylogenesis (8 in triton, 13 in rat, 18 in cat, 16 in dog and 23 in man), although their relative enzymic activity decreases. Isolated multiple forms with high molecular weight enzymatically are classified as acetylcholinesterases. In higher brain structures, multiple forms are more numerous. Butyrylcholinesterases and aliesterases are more abundant in lower brain structures. In the neural plate of the developing triton, it is possible to detect the forms with high specific activity, which exceeds that in adult animals.