Photomicrographs of Fos-like immunoreactivity in the striatum (top row), subthalamic nucleus (middle row), and entopeduncular nucleus (bottom row) after administration of saline (A,A′, A") or m-CPP (B, B′, B") in rats with a sham lesion, and administration of m-CPP in rats with a 6-OHDA lesion (C, C′, C"). Scale bar (in A): A–C", 100 μm.