Fig 1. Binding of IgG from patients to orexin neurons on paraformaldehyde-fixed rat brain tissue sections.

Co-localisation of serum IgG binding and orexin immunoreactivity was optimised using autoimmune disease and healthy control sera. In four marcolepsy patient sera, identified as reactive on the initial immunofluorescence screen, the patient serum IgG binding co-localised with commercial antibody to orexin, but there was also binding to other non-orexin neurons.