Nuclear pore complexes in cells of the developing mouse cerebral cortex

The nuclear pore complexes of cells of the superficial layers of the cerebral cortex of mice were studied by freeze-etch technique. The nuclear membrane was found to be randomly penetrated by typical octagonal pore complexes in all age groups studied. The density of pores (per micron2) amounted to 7.8, 14.0, 17.0, 18.1 and 14.1 on the 18th to 20th embryonic and the 8th, 15th, 50th and 180th postnatal day respectively. The total number of pores per nucleus increases 5.2 times from the 18th to 20th prenatal to the 15th postnatal day and then decreases toward the 180th postnatal day (1257, 6582 and 3385 pores per nucleus respectively). The density of pores in cells of brain cortex, found in young adult mice is relatively high, if compared with other cell types.