We report on structural variability of granule cells in the human dentate gyrus. Granule cells with basal and recurrent dendrites are a normal finding in the human brain. We detect 28.3% granule cells with basal dendrites in non-psychiatrically ill humans compared to rats (2%) and primates (10%). This can be seen as an indication for the higher phylogeny of the human brain. In addition we find a significantly higher incidence of granule cells with basal dendrites (45.7%) in brains of schizophrenic patients. Whereas drug influences during lifetime cannot fully be excluded, we tend to interpret this finding as a plastic reaction to prenatal developmental malformations of the impinging rostral entorhinal region.