Studies on the mode of tangential migration of developing GABAergic neurons, with special reference to their birthdate

Appropriate arrangement of neurons in the cerebral cortex during development is important to establish higher functions in adulthood such as learning and memory. During development, neurons migrate from their born site to their final destination. There are excitatory projection neurons and inhibitory interneurons in the cerebral cortex. These two types of neurons migrate with each characteristic mode of migration. Projection neurons are born in the ventricular zone and migrate radially to their final position in the cerebral cortex, whereas GABAergic neurons are born in the medial ganglionic eminence (MGE) and migrate tangentially to the cortex. The mode of tangential migration seems to be more complicated than that of radial migration. There seems to be lack of detailed information about the mode of tangential migration. In the present study, we examined mode of tangential migration of developing GABAergic neurons which were destined to be cortical GABAergic neurons, with special reference to their birth date, by using BrdU (bromodeoxyuridine, which is incorporated into cells of mitotic phase) labeling