Postnatal development of the glutamate vesicular transporter VGLUT1 in rat cerebral cortex

The expression of the vesicular glutamate transporter VGLUT1 in the rat neocortex was studied during postnatal development using immunocytochemistry and Western blotting. At all ages, VGLUT immunoreactivity is localized to puncta that coexpress the presynaptic marker synaptophysin. VGLUT1 immunoreactivity is faint at birth, increases in the subplate during the first postnatal week, invades the supragranular layers in the second week and reaches the adult pattern at P20-P30. Its spatial and temporal maturation patterns suggest that VGLUT1 may be the vesicular transporter in developing corticocortical connections.