A novel circadian behavior rhythm in arrhythmic triple knockout mice revealed by constant light exposure.

The current model for autonomous circadian oscillation is based on the transcriptional-translational feedback loops of circadian genes. The deletion of one of the circadian genes and its paralogs leads to arrhythmicity. triple knockout ( KO) mice exhibit arrhythmic behavior in constant darkness.

Multiple oscillators underlie circadian food anticipation in mice.

Circadian pacemakers orchestrate behavioral and physiological rhythms, enabling organisms to anticipate daily reoccurring environmental events such as light and dark, temperature changes, and food availability. When nocturnal rodents are subjected to time-restricted feeding during the day, they typically display food anticipatory activity several hours before mealtime. Upon releasing mice to ad libitum feeding, this anticipatory activity is abolished immediately but, following food deprivation, reappears at approximately the same time.

A single incidental dark pulse during daytime attenuated food anticipatory behavior.

Using an open-source operant feeding device (FED3), we measured food-seeking nose poking behavior in mice. When the mice were exposed to 4 h restricted feeding at night, all mice exhibited robust food anticipatory nose poking starting ~4 h before scheduled mealtime. When the light-dark cycle was advanced by 6 h, mice exhibited two distinct bouts of anticipatory poking, one corresponding to actual mealtime which continued at the same time of day, and one corresponding to predicted mealtime which shifted parallel with the light-dark cycle.

Protocol to study circadian food-anticipatory poking in mice using the feeding experimentation device version 3.

Food-anticipatory nose poking is a unique food-seeking behavior driven by the food-entrainable oscillator. Here, we present a protocol to record a novel food-seeking nose poking behavior in mice under temporally restricted feeding followed by food deprivation using the open-source feeding experimentation device version 3 (FED3). We describe steps for setting up the FED3 and cage, training, and habituation.

Gut microbiota depletion minimally affects the daily voluntary wheel running activity and food anticipatory activity in female and male C57BL/6J mice.

Emerging evidence has highlighted that the gut microbiota plays a critical role in the regulation of various aspects of mammalian physiology and behavior, including circadian rhythms. Circadian rhythms are fundamental behavioral and physiological processes that are governed by circadian pacemakers in the brain. Since mice are nocturnal, voluntary wheel running activity mostly occurs at night.

A time memory engram embedded in a light-entrainable circadian clock.

A longstanding mystery in chronobiology is the location and molecular mechanism of the food-entrainable oscillator (FEO). The FEO is an enigmatic circadian pacemaker that controls food anticipatory activity (FAA). The FEO is implicated as a circadian oscillator that entrains to feeding time.