The cerebral cortex of the new-born guinea pig. A quantitative Golgi study of the layer V pyramidal cell.

Quantitative studies have been performed in pyramidal cells (layer V) of the guinea pig's cerebral cortex when the animal were still-born and then not influenced by external sensorial stimuli nor by environment experience. Results related to basal ramifications of the pyramidal cells are similar to those reported in other species. Dendritic spines showed an increased in density along the length of the apical dendrites in a logarithmic regression. A similar pattern of distribution of dendritic spines along the apical dendrite was observed in a given animal, but interindividual variability was demonstrated.