Olanzapine increases cell mitotic activity and oligodendrocyte-lineage cells in the hypothalamus

▶ Atypical antipsychotic agent, olanzapine, has a side effect to induce unwanted weight gain. ▶ Mice treated with olanzapine gained weights with increased food intake, while haloperidol did not show such effects. ▶ Olanzapine-treated mice had more hypothalamic progenitors than control and these progenitors were of oligodendrocytic lineage. ▶ Enhancement of hypothalamic progenitor mitosis resulted in weight gain and increased food intake, suggesting that oligodendrocytic progenitors may be linked to the side effect of olanzapine.