Photoperiodic regulation of satiety mediating neuropeptides in the brainstem of the seasonal Siberian hamster (Phodopus sungorus)

Michael Helwig, Zoe A. Archer, Gerhard Heldmaier, Alexander Tups, Julian Mercer, Martin Klingenspor

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Central regulation of energy balance in seasonal mammals such as the Siberian hamster is dependent on the precise integration of short-term satiety information arising from the gastrointestinal tract with long-term signals on the status of available energy reserves (e.g. leptin) and prevailing photoperiod. Within the central nervous system, the brainstem nucleus of the solitary tract (NTS) and the parabrachial nucleus (PBN) are major relay nuclei that transmit information from the gastrointestinal tract to higher forebrain centres. We extended studies on the seasonal programming of the hypothalamus to examine the effect of the photoperiod on neuropeptidergic circuitries of this gut-brain axis. In the NTS and PBN we performed gene expression and immunoreactivity (-ir) studies on selected satiety-related neuropeptides and receptors: alpha-melanocyte stimulating hormone, melanocortin-3 receptor, melanocortin-4 receptor (MC4-R), growth hormone secretagogue-receptor, cocaine- and amphetamine-regulated transcript, preproglucagon (PPG), glucagon-like peptide 1 (GLP-1), cholecystokinin (CCK), peptide YY, galanin, neurotensin, and corticotrophin releasing hormone (CRH). Gene expression of PPG and MC4-R, and -ir of CCK and GLP-1, in the NTS were up-regulated after 14 weeks in long-day photoperiod (16 h light:8 h dark) compared to short-days (8 h light:16 h dark), whereas CRH-ir and NT-ir were increased in short-days within the PBN. We suggest that brainstem neuroendocrine mechanisms contribute to the long-term regulation of body mass in the Siberian hamster by a photoperiod-related modulation of satiety signalling.

Original languageEnglish
Pages (from-to)631-642
Number of pages12
JournalJournal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology
Volume195
Issue number7
DOIs
Publication statusPublished - Jul 2009

Keywords

  • Seasonal body weight regulation
  • Brainstem
  • Photoperiod
  • Siberian hamster
  • Neuropeptides
  • RECEPTOR MESSENGER-RNA
  • CENTRAL-NERVOUS-SYSTEM
  • NUCLEUS-TRACTUS-SOLITARIUS
  • GLUCAGON-LIKE PEPTIDE-1
  • BODY-WEIGHT
  • PARABRACHIAL NUCLEUS
  • FOOD-INTAKE
  • ARCUATE NUCLEUS
  • GENE-EXPRESSION
  • INSITU HYBRIDIZATION
  • Seasonal body weight regulation
  • Brainstem
  • Photoperiod
  • Siberian hamster
  • Neuropeptides

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