External acetylcholinesterase of the brain in the ontogenesis of maturely and immaturely born rodents.

The fraction of external acetylcholinesterase (AChE) in various divisions of the brain was studied in maturely and immaturely born rodents. It was established that in maturely born rodents (guinea pigs) the fraction of external AChE in all the investigated division of the brain is the same by the time of birth of the animals as in the adults. In immaturely born rodents (white rats), by the moment of birth the fraction of external AChE is significantly higher than in adults. As the brain matures there is a decrease in the proportion of external AChE, most pronounced in the forebrain. It is suggested and experimentally confirmed (in experiments with detergents) that the decrease in the fraction of external AChE is associated with a strengthening of the fixation of the enzyme in the membrane.