Supraoptic nucleus. Photomicrographs of orexin A cell bodies in the supraoptic nucleus (SO) of the Long-Evans rat (A), grass rat (B), and Syrian hamster (C). Note lack of similar cell bodies in the degu (D). OC: optic chiasm. Scale bar = 200 μm.
Nixon and Smale Behavioral and Brain Functions 2007 3:28 doi:10.1186/1744-9081-3-28