Development of Cajal-Retzius cells in the human auditory cortex

We analysed the differentiation and areal distribution of Cajal-Retzius (C-R) cells in the human auditory cortex using acetylcholinesterase (AChE) technique on specimens ranging between 10 weeks of gestation (w.) and the 3rd postnatal month. AChE-reactive cells appear in the marginal zone of the prospective auditory cortex as early as 10 1/2 weeks of gestation. Analysis of primary and associative auditory cortex in subsequent stages of gestation and during early postnatal life reveals an age-dependent decrease in cell-packing density of C-R cells and an increase in thickness of the marginal zone. Large AChE-reactive cells were readily found in the early postnatal cortex. These and our previous data on the human frontal associative cortex demonstrate the presence of AChE-reactive C-R cells in both primary and associative cortical areas during late fetal and early postnatal life. The postnatal changes in the morphology and distribution of AChE-reactive C-R cells may serve as cellular parameters of the postnatal cortical maturation in man.