Fig. 3.
Ketamine induced Fos immunorectivity in the tuberomam-millary nucleus (TMN; A; section counterstained with light Nissl stain), the dorsal raphe nucleus (DRN) nonserotoninergic cells (B; purple immunohistochemical staining for serotonin), the ventral periaqueductal gray matter (vPAG) dopaminergic cells (C; brown immunohistochemical staining for tyroxine hydroxylase), and the laterodorsal tegmental (LDT) noncholinergic cells (D; purple immunohistochemical staining for choline acetyltransferase). Arrows indicate double labeling; arrowheads indicate single labeling (without Fos expression). Scale bar = 200 μm.