Co-localization of hypocretin-1 and hypocretin-2 in the cat hypothalamus and brainstem.
Hypocretin-1 (hcrt-1) and hypocretin-2 (hcrt-2) are two recently discovered hypothalamic neuropeptides. In the present study, using double immunofluorescent techniques, the co-localization of hcrt-1 and hcrt-2 was examined in neuronal soma and fibers/terminals located, respectively, in the cat hypothalamus and brainstem. In the hypothalamus, all hcrt-1 positive neuronal soma also displayed hcrt-2 immunoreactivity. In the brainstem, both hcrt-1 and hcrt-2 antibodies labeled the same fibers/terminals, indicating that hcrt-1 and hcrt-2 co-localize not only in the neuronal soma (hypothalamus) but also in their fibers/terminals (brainstem). If both peptides are released following neuronal activity, then the distinct effects of these peptides in the brain are likely to depend on the types of postsynaptic receptors that are activated.
Department of Physiology and the Brain Research Institute, UCLA School of Medicine, University of California, 53-231 CHS, Los Angeles, CA 90095, USA. zhangjh@ucla.edu
Jian-Hua
JH
Zhang
Sharon
S
Sampogna
Francisco R
FR
Morales
Michael H
MH
Chase
D000818:Animals; D001933:Brain Stem / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D002415:Cats; D005455:Fluorescent Antibody Technique; D007031:Hypothalamus / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides / Q000378:metabolism*; D000068797:Orexins; D017729:Presynaptic Terminals / Q000378:metabolism
D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins