Long QT syndrome type 3 (LQT3) is caused by mutations in the SCN5A-encoded Nav1.5 channel. LQT3 patients exhibit time of day-associated abnormal increases in their heart rate-corrected QT (QTc) intervals and risk for life-threatening episodes. This study determines the effects of uncoupling environmental time cues that entrain circadian rhythms (time of light and time of feeding) on heart rate ...

Traits used for identification of replacement beef heifers and feeding levels provided during postweaning development may have major financial implications due to effects on maintenance requirements and level of lifetime production. The current study evaluated the effects of 2 levels of feeding during the postweaning period on growth, G:F, and ultrasound carcass measurements of heifers, and the...

Smaller guts and slow initial mass gains at stopover sites have led to the idea that digestive physiology limits refueling rates in migrating birds. We tested the digestive-limitation hypothesis in yellow-rumped warblers using food restriction to simulate infrequent feeding during migration, which may cause a reduction in alimentary tract mass. Restricted birds had small intestine, pancreas, an...

The central melanocortin system is conserved across vertebrates. However, in birds, little is known about how energy balance influences orexigenic agouti-related protein (AGRP) and anorexigenic pro-opiomelanocortin (POMC) expression, despite the fact that commercial food restriction is critical to the efficient production of poultry meat. To enable contrasts to be made, in broiler-breeder chick...

Circadian rhythms optimize physiology and health by temporally coordinating cellular function, tissue function, and behavior. These endogenous rhythms dampen with age and thus compromise temporal coordination. Feeding-fasting patterns are an external cue that profoundly influence the robustness of daily biological rhythms. Erratic eating patterns can disrupt the temporal coordination of metabol...

Food anticipatory activity (FAA) is an output of the food-entrained oscillator (FEO), a conspicuous biological clock that expresses when experimental animals are under a restricted food schedule (RFS). We have shown that the liver is entrained by RFS and exhibits an anticipatory response before meal time in its oxidative and energetic state. The present study was designed to determine the mitoc...

While the SCN controls the circadian clock, further evidence suggests the existence of a food-entrainable oscillator (FEO) that links behavior to changes in food availability such as during restricted feeding (RF). We found that the activity of AgRP/NPY neurons changed rhythmically during RF suggesting that these neurons are a component of the FEO. We next ablated AgRP/NPY neurons in neonates w...

Circadian clocks orchestrate periods of rest or activity and feeding or fasting over the course of a 24-hour day and maintain homeostasis. To assess whether a consolidated 24-hour cycle of feeding and fasting can sustain health, we explored the effect of time-restricted feeding (TRF; food access limited to daytime 12 hours every day) on neural, peripheral, and cardiovascular physiology in Droso...