[Histochemical and biochemical study of the hippocampus and neocortex of the wistar rat. II. The activity of carboxylic acid esterases and transmitter enzymes after a learning experiment].

In the present paper the behaviour of the enzymes monoaminoxidase, GABA-transaminase, acetylcholinesterase, nonspecific cholinesterase, A-, B-, C-esterase and acid phosphatase was investigated by histochemical and biochemical methods for 1 min, 1, 4 and 24 h after a "brightness-discrimination" of male wistar rats in a Y-chamber. Learning induced significant changes of activity of the B-esterase in the hippocampus region 4 h (increase of 30%) and 24 h (decrease of 25%) and of the acetylcholinesterase in the cingular cortex 4 h after training (increase of 38%) are to be observed and regarded and discussed as hints for a changed protein synthesis (B-esterase) or altered synaptic activity (acetylcholinesterase). On the strength of these results and various findings in the literature it may be reputed as sure, that the protein synthesis of the cells of hippocampus in evident. Certain proteins show increased rates of synthesis by the influence of a learning experiment. These proteins are at least partially enzymes, serving as extension of the protein synthesis apparatus of the neurons and may be regarded as part mechanism of the intracellular regulation of the synaptic connectivity.