Representative images of traced masseter premotor neurons on coronal sections. Sections were counterstained with fluorescent Nissl (blue). Labeled neurons are observed bilaterally in the dorsal intermediate reticular nucleus (dorsal IRt), in dorsomedial part of spinal trigeminal nucleus (DMSpV) at the anterior-posterior level between VII and XII (A), bilaterally in the dorsal IRt, parvicellular reticular nucleus (PCRt) at the anterior-posterior level of VII (B), contralaterally in the dorsal IRt at the anterior-posterior level of the anterior part of XII (C), PCRt (D), supratrigeminal region (SupV), dorsal principal trigeminal nucleus (PrV) (E), ipsilateral mesencephalic nucleus (MeV) (F), PCRt, dorsal PrV (C), gigantocellular reticular nucleus (Gi) (D), SupV (E), and the contralateral medial subnucleus of deep cerebellar nucleus (DCN) (G). Scale bars, 200 µm.