The roles of orexinergic system (orexin-A, orexin-B) and their receptors (orexin receptor type-1, orexin receptor type-2) in various physiological processes such as arousal, reward seeking behavior, energy homeostasis, sensory modulation, stress processing, cognition, endocrine functions, visceral functions and pain modulation have been established.
In addition, LTD was dependent on the NMDA receptor, as the NMDA receptor antagonist D-AP5 blocked the maintenance of LTD. Our study suggests that orexins, via activation of both OX1 and OX2, play a significant role in the expression of NMDA-dependent LTD, thereby contributing to the spinal modulation of pain transmission.
Here, the role of vlPAG OX1Rs and their interaction with cannabinoid 1 (CB1) receptor was evaluated in anxiety-like behavior following capsaicin-induced dental pulp pain.