The present invention addresses the problem of providing a novel use of pluripotent stem cells (Muse cells) for medical purposes in regenerative medicine. The present invention provides a cell preparation and a pharmaceutical composition both for ameliorating and treating perinatal brain damage including learning disability and motor disability, each of the cell preparation and the pharmaceutical composition containing SSEA-3-positive pluripotent stem cells isolated from a mesenchymal tissue collected from a living body or cultured mesenchymal cells. The cell preparation according to the present invention relies on a mechanism that Muse cells are administered to a subject having the above-mentioned damage to cause the engraftment of the Muse cells in a damaged brain tissue, thereby ameliorating and treating the damage.
