We studied the distribution of glial fibrillary acidic protein (GFAP) and neuron-specific nuclear histone protein NeuN in sulci of the brain cortex during the pre- and postnatal ontogeny. The expression of GFAP during morphogenetic development of the sulci and gyri is cyclic. After functional reorientation of GFAP in human fetuses at weeks 28-30 it ceases to be a marker of morphogenetically active glia and becomes a marker of glial cells exclusively. Redistribution of NeuN expression in different layers of sulci during their formation was found: enhanced expression of NeuN in the cortical layer 6 of sulci and its reduced expression in the upper layers were noted, whereas outside the cortical sulci NeuN expression was similar in all layers. At weeks 24-25 of gestation, NeuN serves as a marker of ingrowth of secondary visual fibers from the dorsal thalamus.