Involvement of hypocretin neurons in multiple system atrophy.
Hypocretin/Orexin (Hcrt/Orx) neurons of the posterolateral hypothalamus have been implicated in control of sleep and autonomic function. Sleep disorders and autonomic failure are important manifestations of multiple system atrophy (MSA). We sought to determine whether Hcrt/Orx neurons were involved in this disorder. Hypothalamus was obtained from seven subjects with neuropathologically confirmed MSA, and seven age-matched controls. 50 mum sections obtained throughout the posterior hypothalamus were immunostained for Hcrt-1 and alpha-synuclein. In MSA, there was a marked reduction of the total numbers of Hcrt/Orx neurons compared to controls (1,009 +/- 190 cells in MSA vs. 3,206 +/- 185 in controls, P < 0.0001). There were abundant glial cytoplasmic inclusions in the area of distribution of Hcrt/Orx neurons in MSA. This is the first demonstration of loss of Hcrt/Orx neurons in MSA, which is consistent with a system degeneration of neurons involved in homeostatic function, including sleep and autonomic regulation, in this disorder.
Benarroch
Eduardo E
EE
Department of Neurology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA. benarroch.eduardo@mayo.edu
Schmeichel
Ann M
AM
Sandroni
Paola
P
Low
Phillip A
PA
Parisi
Joseph E
JE
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002452:Cell Count / Q000379:methods; D005260:Female; D006801:Humans; D007031:Hypothalamus / Q000473:pathology*; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000378:metabolism / Q000473:pathology*; D009474:Neurons / Q000378:metabolism*; D009479:Neuropeptides / Q000378:metabolism*; D000068797:Orexins
D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins