Abstract: Those provided here are an Activin A-containing solution for making inhibitory neuron progenitors proliferate, a method for culturing the inhibitory neuron progenitors using this solution, a method for separating the inhibitory neuron progenitors and the inhibitory neurons using an Activin A receptor Acvr1 expression as an index, a method for transplanting thus separated cells to the brain surface, and a method for screening a factor for making the inhibitory neuron progenitors proliferate.

Abstract: To treat epilepsy or schizophrenia by transplanting precursor cells of GABAergic neurons into a region where GABAergic neurons are lost or decreased in the brain of a patient suffering from the disease, it is intended to provide a method for separating a precursor cell of GABAergic neuron in an adult or a fetal nerve tissue or a precursor cell of GABAergic neuron derived from an embryo stem cell.

Abstract: This invention provides cell kits characterized by comprising oligodendrocytes or oligodendrocyte precursors, and cells producing a substance promoting the migration of these cells. The cell kits can be used in re-myelination treatment of a demyelinated central nerve system (a spinal cord, a brain, an optic nerve and the like).