Hypothalamic Hypocretin (Orexin): Robust Innervation of the Spinal Cord

• DOI: 10.1523/jneurosci.19-08-03171.1999
• Publication Date: 2018-04-03T12:45:53Z
• Authors: Anthony N. van de...
• Keywords: Neuroanatomy

Hypocretin (orexin) is synthesized by neurons in the lateral hypothalamus and has been reported to increase food intake regulate neuroendocrine system. In present paper, long descending axonal projections that contain hypocretin were found innervate all levels of spinal cord from cervical sacral segments, as studied mouse, rat, human not previously described. High densities innervation are regions related modulation sensation pain, notably marginal zone (lamina 1). Innervation intermediolateral column lamina 10 well strong caudal region suggest may participate regulation both sympathetic parasympathetic parts autonomic nervous Double-labeling experiments mice combining retrograde transport diamidino yellow after injections immunocytochemistry support concept hypocretin-immunoreactive fibers originate hypothalamus. Digital-imaging physiological studies with fura-2 detected a rise intracellular calcium response cultured rat neurons, indicating express hypocretin-responsive receptors. A greater number responded than another hypothalamo-spinal neuropeptide, oxytocin. These data addition possible roles feeding endocrine regulation, fiber system play role sensory input, particularly pain perception tone.