The neurogenesis of the callosal population of cortical cells in hamsters

The neurogenesis of the callosal subpopulation of cortical cells was determined in hamsters by associating incorporation of [3H]-thymidine injected on different embryonic days with horseradish peroxidase retrograde labelling in adulthood. Despite the great radial dispersion of migratory destinations of neurons born simultaneously, it was found that callosal birthdates in cortical area 6 extend from day E13 to day E15, a period that corresponds to the neurogenesis of layers III-V, where most callosal neurons come to be located in adults.