Figure 10From: Mapping of neurokinin-like immunoreactivity in the human brainstemA. NK-ir perikarya (arrows) and fibers (arrowheads) in the periaqueductal gray (PAG). D: dorsal; M: medial. Scale bar: 100 Ī¼m B. A low density of immunoreactive fibers is observed in layer 1 of the superior colliculus (SC), whereas a high density is located in layer 2. D: dorsal; M: medial. Scale bar: 100 Ī¼mBack to article page