[Quantitative study of primitive pyramidal cells in rat anterior cingular cortex].

In the present paper the primitive pyramidal cells of the Vthlayer of the anterior cingulate cortex in adult male white rats were analyzed quantitatively and compared statisticaly with large pyramidal cells of the same region. The number of dendrites, the total lengths of dendrites, the number of spines and the density of spines -- according to the order of dendrites -- show similarity between the primitive pyramidal cells and the large pyramidal cells the latter one exhibit the higher values. The curves of distribution of the various density of spines along the apical main dendrite of both cell types are similar in shape, too. The lengths of the dendritic fields and their basal spines-values are without significant distinction for both cell types, however there are more dendritic fields in large pyramidal cells. Refered to a complete pyramidal neuron they can say: there are significantly higher values in large pyramidal cells for the number of dendrites and their total lengths, the total number of spines, the number of branching sites sites and free endings. However the density of spines of the complete neuron has no significant differences between primitive and large pyramidal cells.