title: Differential sensitivity of GABAergic and glycinergic inputs to orexin-A in preganglionic cardiac vagal neurons of newborn rats.
abstract: OBJECTIVE
  To test the effect of orexin-A (hypocretin-1), a neuropeptide synthesized in the lateral hypothalamus and the perifornical area, on the glycinergic inputs and the GABAergic inputs of cardiac vagal neurons (CVN).
  
  
  METHODS
  The effects of orexin-A at three concentrations (20 nmol/L, 100 nmol/L, 500 nmol/L) on the glycinergic inputs and the GABAergic inputs were investigated by using retrograde fluorescent labeling of cardiac neurons (CVN) in the nucleus ambiguus (NA) and the voltage patch-clamp technique.
  
  
  RESULTS
  Orexin-A dose-dependently increased the frequency of both the glycinergic and the GABAergic spontaneous inhibitory postsynaptic currents (sIPSC). However, at a lower concentration (20 nmol/L) of orexin-A, although the frequency of the glycinergic sIPSC was significantly increased, the frequency of the GABAergic sIPSC was not significantly changed.
  
  
  CONCLUSIONS
  The glycinergic inputs and the GABAergic inputs have different sensitivities to orexin-A, which suggests that the two kinds of inhibitory inputs might play different roles in the synaptic control of cardiac vagal functions.
authors.affiliation: National Key Laboratory of Medical Neurobiology, Fudan University Shanghai Medical College, Shanghai 200032, China. wangjj@shmu.edu.cn
authors.forename: Ji-Jiang
authors.initials: JJ
authors.lastname: Wang
authors.forename: Yong-Hua
authors.initials: YH
authors.lastname: Chen
authors.forename: Ke-Yong
authors.initials: KY
authors.lastname: Li
authors.forename: Feng-Yan
authors.initials: FY
authors.lastname: Sun
mesh_terms: D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000818:Animals; D004305:Dose-Response Relationship, Drug; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects*; D018756:GABA Antagonists / Q000494:pharmacology; D005998:Glycine / Q000502:physiology; D006321:Heart / Q000187:drug effects / Q000294:innervation*; D047908:Intracellular Signaling Peptides and Proteins / Q000008:administration & dosage / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D009479:Neuropeptides / Q000008:administration & dosage / Q000494:pharmacology*; D000068797:Orexins; D010852:Picrotoxin / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D009435:Synaptic Transmission; D014630:Vagus Nerve / Q000166:cytology / Q000502:physiology*; D005680:gamma-Aminobutyric Acid / Q000502:physiology
chemical_list: D015763:2-Amino-5-phosphonovalerate; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione; D018691:Excitatory Amino Acid Antagonists; D018756:GABA Antagonists; D005998:Glycine; D047908:Intracellular Signaling Peptides and Proteins; D009479:Neuropeptides; D000068797:Orexins; D010852:Picrotoxin; D005680:gamma-Aminobutyric Acid