text: On the other hand, high doses of okadaic acid (10 ng/mouse, i.c.v.) and cantharidin (1 microg/mouse, i.c.v.), which also block PP1, and << calyculin-A >> (0.1 fg/mouse-1 ng/mouse, i.c.v.), which inhibits equally both [[ PP1 ]] and PP2A, did not modify the morphine-induced antinociception.