The Running Wheel Enhances Food Anticipatory Activity: An Exploratory Study

Abstract

Rodents anticipate rewarding stimuli such as daily meals, mates, and stimulant drugs. When a single meal is provided daily at a fixed time of day, an increase in activity, known as food anticipatory activity (FAA), occurs several hours before feeding time. The factors affecting the expression of FAA have not been well-studied. Understanding these factors may provide clues to the undiscovered anatomical substrates of food entrainment. In this study we determined whether wheel-running activity, which is also rewarding to rodents, modulated the robustness of FAA. We found that access to a freely rotating wheel enhanced the robustness of FAA. This enhancement was lost when the wheel was removed. In addition, while prior exposure to a running wheel alone did not enhance FAA, the presence of a locked wheel did enhance FAA as long as mice had previously run in the wheel. Together, these data suggest that FAA, like wheel-running activity, is influenced by reward signaling.

mPeriod2 Brdm1 and other single Period mutant mice have normal food anticipatory activity

“…We have also previously shown that food anticipatory is more robust in long photoperiods (18 L:6D) compared to 12 L:12D. If we had performed our experiments in 18L:6D, we may have reduced the individual variability in the robustness of food anticipatory activity in both wild-type and mPer2 Brdm1 −/− mice 17 , 18 .…”

“…Second, we fed the mice beginning at ZT5 or ZT6, while previous studies sometimes began restricted feeding at ZT4 10 , 12 . We previously showed that the phase of restricted feeding regulated the robustness of food anticipatory activity so incremental changes in the phase of restricted feeding could permit or conceal the expression of anticipatory activity 17 . Finally, we measured wheel-running food anticipatory activity, which enhances food anticipatory activity compared to mice without running wheels 17 .…”

“…We previously showed that the phase of restricted feeding regulated the robustness of food anticipatory activity so incremental changes in the phase of restricted feeding could permit or conceal the expression of anticipatory activity 17 . Finally, we measured wheel-running food anticipatory activity, which enhances food anticipatory activity compared to mice without running wheels 17 . Thus, it appears that the combination of an aggressive restricted feeding protocol (4-h/day) at mid-day phases (ZT6-10 and ZT5-9) with running wheels permitted the detection of food anticipatory activity in mPer2 Brdm1 −/− mice in the current study.…”

Scheduled meal accelerates entrainment to a 6‐h phase advance by shifting central and peripheral oscillations in rats

“…Other studies have suggested that the adjustment to daily cycles depends on the integration of multiple Zeitgebers in addition to the LD cycle (Blum et al ., ; Webb et al ., ). Re‐entrainment acceleration has been tried in experimental models of jet lag, using scheduled access to an activity wheel (Castillo et al ., ; Flores et al ., ) giving corticosterone (Kiessling et al ., ) or with scheduled melatonin (Ángeles‐Castellanos et al ., ; Pfeffer et al ., ). This study provides evidence that food is an efficient entraining signal for the circadian system entrainment is achieved via shifting the activity of central structures, thus mediating metabolic and autonomic responses that synchronize extra‐SCN oscillations to the mealtime.…”

Sincronização fótica e não fótica dos ritmos circadianos em roedores subterrâneos (Ctenomys aff. knighti) e roedores modelo de laboratório (Mus musculus)

“…Still, many factors have been identified, which either inhibit or stimulate the expression of FAA (Flôres et al, 2016c). It is evident now that at least two aspects revolve around the expression of FAA: metabolism and reward.…”