The expression and significance of three types of Fos- like im munoreactive(L i) cells were investigated after gamma knife ir-radiation of the forebrain in the rat. Three months after the irradiation,the brain sections were immunostained with an anti-seru The expression and significance of three types of Fos-like im munoreactive (Li) cells were investigated after gamma knife ir-radiation of the forebrain in the rat. Three months after the irradiation, the brain sections were immunostained with an anti-seru