[External brain acetylcholinesterase in the ontogeny of precocial and altricial rodents].

The share of external acetylcholinesterase (AChE) has been determined in different brain structures of maturely and immaturely born rodents. It was found that in maturely born animals (guinea pigs) the share of external AChE in all the studied brain structures is the same in newborn and adult individuals. In immaturely born animals (albino rats) the share of external AChE to the moment of birth is significantly higher as that in adult organisms. During the development of the brain, the share of the external enzyme decreases, the decrease being more evident in the forebrain. It is suggested that this decrease is associated with fixation of the enzyme to the membrane, which is indicated in particular by the experiments with detergents.