期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1998
卷号:95
期号:3
页码:1242-1246
DOI:10.1073/pnas.95.3.1242
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:The evolutionary expansion of neocortical size in mammals is particularly prominent in anthropoid primates (i.e., monkeys, apes, and humans) and reflects an increased number of cortical cells, yet the developmental basis for this increase remains undefined. Cortical cell production depends on the length of the cell-division cycle of progenitor cells during neurogenesis, which previously has been measured only in smaller-brained rodents. To investigate whether cortical expansion in primates reflects modification of cell-cycle kinetics, we determined cell-cycle length during neurogenesis in the proliferative cerebral ventricular zone of fetal rhesus monkeys, by using cumulative S-phase labeling with bromodeoxyuridine. Cell-cycle durations in monkeys were as much as 5 times longer than those reported in rodents. Nonetheless, substantially more total rounds of cell division elapsed during the prolonged neurogenetic period of the monkey cortex, providing a basis for increased cell production. Moreover, unlike the progressive slowing that occurs during cortical development in rodents, cell division accelerated during neurogenesis of the enlarged cortical layers in monkeys. These findings suggest that evolutionary modification of the duration and number of progenitor cell divisions contributed to both the expansion and laminar elaboration of the primate neocortex.