title: Human hypocretin and melanin-concentrating hormone levels are linked to emotion and social interaction.
abstract: The neurochemical changes underlying human emotions and social behaviour are largely unknown. Here we report on the changes in the levels of two hypothalamic neuropeptides, hypocretin-1 and melanin-concentrating hormone, measured in the human amygdala. We show that hypocretin-1 levels are maximal during positive emotion, social interaction and anger, behaviours that induce cataplexy in human narcoleptics. In contrast, melanin-concentrating hormone levels are minimal during social interaction, but are increased after eating. Both peptides are at minimal levels during periods of postoperative pain despite high levels of arousal. Melanin-concentrating hormone levels increase at sleep onset, consistent with a role in sleep induction, whereas hypocretin-1 levels increase at wake onset, consistent with a role in wake induction. Levels of these two peptides in humans are not simply linked to arousal, but rather to specific emotions and state transitions. Other arousal systems may be similarly emotionally specialized.
authors: Department of Psychiatry and Biobehavioral Sciences, University of California at Los Angeles, Los Angeles, California 90095, USA.
authors: Ashley M
authors: AM
authors: Blouin
authors: Itzhak
authors: I
authors: Fried
authors: Charles L
authors: CL
authors: Wilson
authors: Richard J
authors: RJ
authors: Staba
authors: Eric J
authors: EJ
authors: Behnke
authors: Hoa A
authors: HA
authors: Lam
authors: Nigel T
authors: NT
authors: Maidment
authors: Karl Æ
authors: KÆ
authors: Karlsson
authors: Jennifer L
authors: JL
authors: Lapierre
authors: Jerome M
authors: JM
authors: Siegel
mesh_terms: D000328:Adult; D000679:Amygdala / Q000378:metabolism; D000818:Animals; D001519:Behavior; D004567:Electrodes, Implanted; D004644:Emotions / Q000502:physiology*; D005260:Female; D006801:Humans; D007028:Hypothalamic Hormones / Q000378:metabolism*; D007031:Hypothalamus / Q000378:metabolism; D007398:Interpersonal Relations; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D008297:Male; D008543:Melanins / Q000378:metabolism*; D017551:Microdialysis; D008875:Middle Aged; D009479:Neuropeptides / Q000378:metabolism*; D000068797:Orexins; D010907:Pituitary Hormones / Q000378:metabolism*; D051381:Rats; D012890:Sleep / Q000502:physiology; D013997:Time Factors; D014851:Wakefulness / Q000502:physiology; D055815:Young Adult
chemical_list: C000596229:HCRT protein, human; D007028:Hypothalamic Hormones; D047908:Intracellular Signaling Peptides and Proteins; D008543:Melanins; D009479:Neuropeptides; D000068797:Orexins; D010907:Pituitary Hormones; C019463:melanin-concentrating hormone