title: Effects of ghrelin on gastric distension sensitive neurons and gastric motility in the lateral septum and arcuate nucleus regulation.
abstract: BACKGROUND
  Ghrelin is an endogenous ligand for the growth hormone secretagogue receptor (GHS-R) and a peptide hormone that promotes food intake and gastric motility. Our aims are to explore the effects of ghrelin on gastric distension (GD) sensitive neurons in the lateral septum, and the possible regulation of gastric motility by ghrelin through the hypothalamic arcuate nucleus (ARC).
  
  
  METHODS
  Single-unit discharges were recorded, extracellularly, and the gastric motility was monitored by the administration of ghrelin in the lateral septum. The projection of nerve fiber and expression of ghrelin were observed by retrograde tracer and fluo-immunohistochemistry staining. The expression of GHS-R and ghrelin was determined by real-time polymerase chain reaction and western blotting analysis.
  
  
  RESULTS
  There were GD neurons in the lateral septum. The administration of ghrelin could excite both GD-excitatory (GD-E) and GD-inhibitory (GD-I) neurons in the lateral septum. Gastric motility was significantly enhanced by the administration of ghrelin in the lateral septum in a dose-dependent manner. Pretreatment with [D-Lys-3]-GHRP-6, however, could completely abolish the ghrelin-induced effects. Electrical stimulation of the ARC could significantly excite the response of GD neurons to ghrelin, increase ghrelin protein expression in the lateral septum and promote gastric motility. Nevertheless, these effects could be mitigated by pretreatment of [D-Lys-3]-GHRP-6. Electrical lesion of the lateral septum resulted in decreased gastric motility. The GHS-R and Ghrelin/FG-double labeled neurons were observed in the lateral septum and ARC, respectively.
  
  
  CONCLUSIONS
  It is suggested that the lateral septum may receive afferent information from the gastrointestinal tract and promote gastric motility. Ghrelin plays an important role in promoting gastric motility in the lateral septum. The ARC may be involved in the regulation of the lateral septum's influence on gastric motility.
authors.affiliation: Department of Pathophysiology, Medical College of Qingdao University, Qingdao, 266021, Shandong, China.
authors.forename: Yanling
authors.initials: Y
authors.lastname: Gong
authors.forename: Luo
authors.initials: L
authors.lastname: Xu
authors.forename: Feifei
authors.initials: F
authors.lastname: Guo
authors.forename: Mingjie
authors.initials: M
authors.lastname: Pang
authors.forename: Zhenyan
authors.initials: Z
authors.lastname: Shi
authors.forename: Shengli
authors.initials: S
authors.lastname: Gao
authors.forename: Xiangrong
authors.initials: X
authors.lastname: Sun
mesh_terms: D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D004558:Electric Stimulation; D005769:Gastrointestinal Motility / Q000187:drug effects* / Q000502:physiology; D054439:Ghrelin / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D008297:Male; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D009842:Oligopeptides / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D054440:Receptors, Ghrelin / Q000235:genetics / Q000378:metabolism; D012686:Septal Nuclei / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D013270:Stomach / Q000187:drug effects* / Q000294:innervation / Q000502:physiology; D017833:Visceral Afferents / Q000502:physiology
chemical_list: C520836:GHRP-6, Lys(3)-; D054439:Ghrelin; C571124:Ghsr1a protein, rat; D009842:Oligopeptides; D012333:RNA, Messenger; D054440:Receptors, Ghrelin