Cholecystokinin activation of central satiety centers changes seasonally in a mammalian hibernator

Jessica P. Otis, Helen E Raybould, Hannah V. Carey

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

Hibernators that rely on lipids during winter exhibit profound changes in food intake over the annual cycle. The mechanisms that regulate appetite changes in seasonal hibernators remain unclear, but likely consist of complex interactions between gut hormones, adipokines, and central processing centers. We hypothesized that seasonal changes in the sensitivity of neurons in the nucleus tractus solitarius (NTS) to the gut hormone cholecystokinin (CCK) may contribute to appetite regulation in ground squirrels. Spring (SPR), late summer (SUM), and winter euthermic hibernating (HIB) 13-lined ground squirrels (Ictidomys tridecemlineatus) were treated with intraperitoneal CCK (100 μg/kg) or vehicle (CON) for 3. h and Fos expression in the NTS was quantified. In CON squirrels, numbers of Fos-positive neurons in HIB were low compared to SPR and SUM. CCK treatment increased Fos-positive neurons in the NTS at the levels of the area postrema (AP) and pre AP during all seasons and at the level of the rostral AP in HIB squirrels. The highest absolute levels of Fos-positive neurons were found in SPR CCK squirrels, but the highest relative increase from CON was found in HIB CCK squirrels. Fold-changes in Fos-positive neurons in SUM were intermediate between SPR and HIB. Thus, CCK sensitivity falls from SPR to SUM suggesting that seasonal changes in sensitivity of NTS neurons to vagally-derived CCK may influence appetite in the active phase of the annual cycle in hibernating squirrels. Enhanced sensitivity to CCK signaling in NTS neurons of hibernators indicates that changes in gut-brain signaling may contribute to seasonal changes in food intake during the annual cycle.

Original languageEnglish (US)
Pages (from-to)269-274
Number of pages6
JournalGeneral and Comparative Endocrinology
Volume171
Issue number3
DOIs
StatePublished - May 1 2011

Fingerprint

cholecystokinin
Cholecystokinin
Sciuridae
satiety
squirrels
Solitary Nucleus
neurons
Neurons
Area Postrema
appetite
digestive system
summer
Appetite
food intake
Eating
hormones
Hormones
Appetite Regulation
adipokines
Adipokines

Keywords

  • Appetite
  • Cholecystokinin
  • Hibernation
  • Satiety
  • Torpor

ASJC Scopus subject areas

  • Endocrinology

Cite this

Cholecystokinin activation of central satiety centers changes seasonally in a mammalian hibernator. / Otis, Jessica P.; Raybould, Helen E; Carey, Hannah V.

In: General and Comparative Endocrinology, Vol. 171, No. 3, 01.05.2011, p. 269-274.

Research output: Contribution to journalArticle

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