Full text is available at the source.
The Journal of neuroscience : the official journal of the Society for Neuroscience···
Obesity from a High-Fat Diet Disrupts Daily Rhythms in Stomach Nerve Signals
Updated
Abstract
HFD mice consumed more food during the light phase with larger and more frequent meals compared to SLD mice after 12 weeks.
- HFD mice showed little circadian variation in stomach content or gastric vagal afferent (GVA) mechanosensitivity.
- SLD mice exhibited circadian fluctuations in stomach content, peaking at ZT18 and reaching a low at ZT9.
- Leptin enhanced mucosal receptor mechanosensitivity in SLD mice, but this effect was reduced during the dark phase.
- Loss of circadian variation in GVA signaling may be linked to altered eating behavior in HFD-induced obesity.
Simplified
UNLABELLED: Rats with high-fat diet (HFD)-induced obesity increase daytime eating, suggesting an alteration in circadian food intake mechanisms. Gastric vagal afferents (GVAs) respond to mechanical stimuli to initiate satiety. These signals are dampened in HFD mice and exhibit circadian variations inversely with food intake in lean mice. Furthermore, leptin shows circadian variation in its circulating level and is able to modulate GVA mechanosensitivity. However, whether leptin's ability to modulate GVAs occurs in a circadian manner is unknown. Therefore, we investigated whether changes in the circadian intake of food in HFD-induced obesity is associated with a disruption in GVA circadian rhythms. Eight-week-old male C57BL/6 mice were fed a standard laboratory diet (SLD) or a HFD for 12 weeks. A subgroup of SLD and HFD mice were housed in metabolic cages. After 12 weeks, ex vivo GVA recordings were taken at 3 h intervals starting at zeitgeber time 0 (ZT0) and stomach content was measured. After 12 weeks, HFD mice consumed more food during the light phase through larger and more frequent meals compared with SLD mice. SLD mice exhibited circadian fluctuation in stomach content, which peaked at ZT18 and reached a nadir at ZT9. At these time points, both tension and mucosal receptor mechanosensitivity were the lowest and highest, respectively. HFD mice exhibited little circadian variation in stomach content or GVA mechanosensitivity. Leptin potentiated mucosal receptor mechanosensitivity only in SLD mice and with reduced potency during the dark phase. In conclusion, loss of circadian variation in GVA signaling may underpin changes in eating behavior in HFD-induced obesity.
SIGNIFICANCE STATEMENT: Appropriate circadian control of food intake is vital for maintaining metabolic health. Diet-induced obesity is associated with strong circadian changes in food intake, but the contributing mechanisms have yet to be determined. Vagal afferents are involved in regulation of feeding behavior, particularly meal size, and have been shown to exhibit circadian fluctuation in mechanosensitivity, potentially allowing for time of day-specific levels of satiety signaling. Our study indicates that, in diet-induced obesity, these circadian fluctuations in gastric vagal afferent mechanosensitivity are lost. This was accompanied by increased light phase eating, particularly increased meal size. This is the first evidence that diet-induced disruption to vagal afferent signaling may cause a perturbation in circadian eating patterns.
Related papers
May '18
Time-Restricted Feeding Protects Daily Sensitivity of Stomach Nerve Signals in Obese Mice on a High-Fat Diet
top 5% journal
cited by 39 papers
research support, non-u.s. gov't
Sep '19
Changing the light cycle removes daily rhythms in stomach nerve sensitivity to stretch
cited by 15 papers
comparative study
Jul '13
Changes in stomach nerve sensitivity caused by high-fat diet continue after returning to normal food and are linked to eating more
top 10% journal
cited by 42 papers
journal article
Jun '15
High-fat diet changes stomach nerve response to adiponectin
cited by 21 papers
research support, non-u.s. gov't
Apr '20
Methanandamide’s effect on stomach fullness signals from the vagus nerve changes with nutritional state
top 10% journal
cited by 10 papers
research support, non-u.s. gov't
Aug '15
TRPV1 Channels and Stomach Nerve Signals in Lean and Obese Mice on High Fat Diet
top 30% journal
cited by 50 papers
research support, non-u.s. gov't
Dec '19
Activation of CRF2 receptor increases sensitivity of stomach nerve signals to stretching
cited by 10 papers
journal article
Dec '13
Daily changes in stomach nerve sensitivity to stretch
top 5% journal
cited by 66 papers
research support, non-u.s. gov't
Jan '17
Nesfatin-1 changes stomach nerve sensitivity in mice depending on their nutritional state
cited by 17 papers
journal article
Nov '20
Changes in stomach nerve signals during pregnancy in mice
top 10% journal
cited by 18 papers
research support, non-u.s. gov't