[Dendroarchitectonic study of the pyramidal cells of the medial frontal cortex of the macaca]

A comparative study of "normal" and "improperly oriented" pyramidal cells has been performed in the medial frontal lobe cortex of the monkey (Macacus Irus). The comparison of the observed number of topological types for each group of dendrites shows that the apical dendrites of each type of cells have a different growth. The apical dendrites of the normal pyramidal cells grow by monochotomous branching on random segments and have much more spines on the first order segments, the apical dendrites of the improperly oriented pyramidal cells grow by branching on pendant arcs (terminal growth model), and have fewer spines. The functional signification of these differences remains actually obscure.