title: Hypocretinergic facilitation of synaptic activity of neurons in the nucleus pontis oralis of the cat.
abstract: The present study was undertaken to explore the neuronal mechanisms of hypocretin actions on neurons in the nucleus pontis oralis (NPO), a nucleus which plays a key role in the generation of active (REM) sleep. Specifically, we sought to determine whether excitatory postsynaptic potentials (EPSPs) evoked by stimulation of the laterodorsal tegmental nucleus (LDT) and spontaneous EPSPs in NPO neurons are modulated by hypocretin. Accordingly, recordings were obtained from NPO neurons in the cat in conjunction with the juxtacellular microinjection of hypocretin-1 onto intracellularly recorded cells. The application of hypocretin-1 significantly increased the mean amplitude of LDT-evoked EPSPs of NPO neurons. In addition, the frequency and the amplitude of spontaneous EPSPs in NPO neurons increased following hypocretin-1 administration. These data suggest that hypocretinergic processes in the NPO are capable of modulating the activity of NPO neurons that receive excitatory cholinergic inputs from neurons in the LDT.
authors.affiliation: Department of Physiology and the Brain Research Institute, 53-231 CHS, UCLA School of Medicine, 90095, Los Angeles, CA, USA. mcxi@ucla.edu
authors.forename: Ming Chu
authors.initials: MC
authors.lastname: Xi
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Fung
authors.forename: Jack
authors.initials: J
authors.lastname: Yamuy
authors.forename: Francisco R
authors.initials: FR
authors.lastname: Morales
authors.forename: Michael H
authors.initials: MH
authors.lastname: Chase
mesh_terms: D000109:Acetylcholine / Q000502:physiology; D000818:Animals; D002352:Carrier Proteins / Q000494:pharmacology*; D002415:Cats; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects; D047908:Intracellular Signaling Peptides and Proteins; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D009479:Neuropeptides / Q000494:pharmacology*; D000068797:Orexins; D011149:Pons / Q000166:cytology / Q000187:drug effects*; D012895:Sleep, REM / Q000187:drug effects; D013566:Sympathomimetics / Q000494:pharmacology*; D013569:Synapses / Q000187:drug effects* / Q000502:physiology; D013681:Tegmentum Mesencephali / Q000502:physiology
chemical_list: D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins; D013566:Sympathomimetics; D000109:Acetylcholine