Reduced Numbers of Corticotropin-Releasing Hormone Neurons in Narcolepsy Type 1.

Narcolepsy type 1 (NT1) is a chronic sleep disorder correlated with loss of hypocretin(orexin). In NT1 post-mortem brains, we observed 88% reduction in corticotropin-releasing hormone (CRH)-positive neurons in the paraventricular nucleus (PVN) and significantly less CRH-positive fibers in the median eminence, whereas CRH-neurons in the locus coeruleus and thalamus, and other PVN neuronal populations were spared: that is, vasopressin, oxytocin, tyrosine hydroxylase, and thyrotropin releasing hormone-expressing neurons. Other hypothalamic cell groups, that is, the suprachiasmatic, ventrolateral preoptic, infundibular, and supraoptic nuclei and nucleus basalis of Meynert, were unaffected. The surprising selective decrease in CRH-neurons provide novel targets for diagnostics and therapeutic interventions. ANN NEUROL 2022;91:282-288.