Recent development of the regenerative medicine shed a ray of hope on many human diseases, but not much on the brain disability, yet. To overcome this drawback, we searched new sites of adult neurogenesis in the mouse cranium and found the pia-progenitors on the outer surface of the pia mater (the leptomeninges). By marking a part of the ventricular zone of the pallium with GFP or FucciGreen reporter plasmids at time points of E14-17, we traced the neuron progenitors migrate radially and penetrate the pia mater. These pia-progenitors were inactivated in the leptomeninges and lost GFP and FucciGreen markers as the mice grow. However, brain stress like epilepsy induced by pirokalpin injection i.p. activates pia-progenitors and make them express c-fos in an hour. Kindling induces nestin in a few days, GAD67 and Tuj1, or NEX/Math2/NeuroD6 and Tuj1 in a week. The pia-progenitors proliferate on the surface of the pia mater. As the pia-progenitors proliferate, the leptomeninges showed hypertrophy. We counted the number of c-fos positive cells on the outer surface of the neocortex by stereology and found it reaches 200 thousand. As the mice live longer than 1 year, the number of the c-fos positive cells induced by pirokalpin was reduced into less than half. The ratio between the NEX/Math2/NeuroD6-positive pia-progenitors and the GAD67-positive pia-progenitors was 4:1 roughly. Finally, the pia-progenitors give rise neuron precursors and glia which enter the neocortex.