Migratory Behavior of Presumptive Interneurons Is Affected by AMPA Receptor Activation in Slice Cultures of Embryonic Mouse Neocortex

It has been reported that functional α-amino-3-hydroxy-5-methyl-isoxazolpro-prionic acid (AMPA) receptors permeable to calcium are already expressed by tangentially migrating prospective interneurons in the developing rodent cerebral cortex. However, the role of these receptors is not yet fully understood. To examine the effect of activation of AMPA receptors on tangential migration, we exposed migrating prospective interneurons derived from the medial ganglionic eminence (MGE) to AMPA in slice cultures and performed time lapse imaging. In the neocortex, a subpopulation of MGE-derived cells stopped migration or changed the direction of migration in response to AMPA in a dose-dependent manner. In contrast, neither MGE-derived cells migrating in the subcortical territory nor radially migrating cells in the neocortex were affected by exposure to AMPA. Transfection of dominant-negative AMPA receptor subunit GluR1 to the tangentially migrating cells prevented the effects of AMPA on migration. This study provides evidence that the activation of AMPA receptors can directly affect tangential migration in the neocortical part of telencephalic slice cultures.