Orexin (hypocretin) receptor-expressing neurons play critical roles in wakefulness, arousal, and have been implicated in neurodegenerative processes.
Two orexin receptors exist: OX1R (HCRTR1) and OX2R (HCRTR2). Orexin neurons primarily express OX2R, while target neurons may express either receptor type.
Orexin receptor neurons are found in:
Orexin neuron loss contributes to sleep disturbances in PD. Reduced orexin levels correlate with disease severity.
Orexin system dysregulation may contribute to sleep-wake cycle disturbances common in AD.
Orexin receptor antagonists are used for insomnia; agonists may have neuroprotective potential.