Orexins are synthesized by neurons in the hypothalamus and contribute to multiple
physiological functions. Orexin fibers innervate many regions of the CNS, which include
areas involved in descending control of pain. We examined the role orexins may play in
endogenous modulation of pain transmission using prepro-orexin (precursor of orexin A and
B) knockout mice. Baseline pain thresholds of knockout and wild type mice were not
different. Knockout mice presented greater degree of hyperalgesia induced by peripheral …