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Food-anticipatory activity in Syrian hamsters: behavioral and molecular responses in the hypothalamus according to photoperiodic conditions.

Dantas-Ferreira RF, Dumont S, Gourmelen S, Cipolla-Neto J, Simonneaux V, Pévet P, Challet E - PLoS ONE (2015)

Bottom Line: When food availability is restricted, animals adjust their behavior according to the timing of food access.During FAA under skeleton photoperiods, c-Fos expression was increased in the arcuate nuclei independently of the photoperiod, but differentially increased in the ventromedial and dorsomedial hypothalamic nuclei according to the photoperiod.FAA in general activity was hardly modulated by daytime light, but was reduced under SP.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurobiology of Rhythms, Institute of Cellular and Integrative Neurosciences, UPR 3212 CNRS, University of Strasbourg, Strasbourg, France; Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.

ABSTRACT
When food availability is restricted, animals adjust their behavior according to the timing of food access. Most rodents, such as rats and mice, and a wide number of other animals express before timed food access a bout of activity, defined as food-anticipatory activity (FAA). One notable exception amongst rodents is the Syrian hamster, a photoperiodic species that is not prone to express FAA. The present study was designed to understand the reasons for the low FAA in that species. First, we used both wheel-running activity and general cage activity to assess locomotor behavior. Second, the possible effects of photoperiod was tested by challenging hamsters with restricted feeding under long (LP) or short (SP) photoperiods. Third, because daytime light may inhibit voluntary activity, hamsters were also exposed to successive steps of full and skeleton photoperiods (two 1-h light pulses simulating dawn and dusk). When hamsters were exposed to skeleton photoperiods, not full photoperiod, they expressed FAA in the wheel independently of daylength, indicating that FAA in the wheel is masked by daytime light under full photoperiods. During FAA under skeleton photoperiods, c-Fos expression was increased in the arcuate nuclei independently of the photoperiod, but differentially increased in the ventromedial and dorsomedial hypothalamic nuclei according to the photoperiod. FAA in general activity was hardly modulated by daytime light, but was reduced under SP. Together, these findings show that food-restricted Syrian hamsters are not prone to display FAA under common laboratory conditions, because of the presence of light during daytime that suppresses FAA expression in the wheel.

No MeSH data available.


Related in: MedlinePlus

Food-anticipatory activity in a hamster exposed to a short photoperiod.Panel A: wheel-running activity; panel B: general cage activity. Each line represents 48 h, plotted in 5-min bins. The initial light-dark cycle (10 h of light, 14 h of darkness; full short photoperiod) is indicated by horizontal white and black bars. Zeitgeber time (ZT) 0 corresponds to lights on. Gray shaded areas indicate periods of darkness. Arrows on the right Y axis show the different photoperiodic conditions (Sk: skeleton long photoperiod, comprising 1-h light from ZT 0 to ZT 1 followed by 12-h dark, and then 1-h light from ZT 9 to ZT 10, and 14-h dark; Fu: full short photoperiod, comprising 10 h of light and 14 h of dark). During baseline, hamsters were fed ad libitum (AL). Green shaded areas show the daily 12-h period of food access during restricted feeding (RF), from midday (i.e., ZT 5) to ZT 17. Arrows on the left Y axis show the onset of food restriction. Arrows next to Sk_RF (early) and Sk_RF (late) on the right Y axis show the first and second periods of restricted feeding under Sk, respectively.
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pone.0126519.g003: Food-anticipatory activity in a hamster exposed to a short photoperiod.Panel A: wheel-running activity; panel B: general cage activity. Each line represents 48 h, plotted in 5-min bins. The initial light-dark cycle (10 h of light, 14 h of darkness; full short photoperiod) is indicated by horizontal white and black bars. Zeitgeber time (ZT) 0 corresponds to lights on. Gray shaded areas indicate periods of darkness. Arrows on the right Y axis show the different photoperiodic conditions (Sk: skeleton long photoperiod, comprising 1-h light from ZT 0 to ZT 1 followed by 12-h dark, and then 1-h light from ZT 9 to ZT 10, and 14-h dark; Fu: full short photoperiod, comprising 10 h of light and 14 h of dark). During baseline, hamsters were fed ad libitum (AL). Green shaded areas show the daily 12-h period of food access during restricted feeding (RF), from midday (i.e., ZT 5) to ZT 17. Arrows on the left Y axis show the onset of food restriction. Arrows next to Sk_RF (early) and Sk_RF (late) on the right Y axis show the first and second periods of restricted feeding under Sk, respectively.

Mentions: Locomotor activity was assessed by both wheel-running activity and general cage activity (Figs 2 and 3).


Food-anticipatory activity in Syrian hamsters: behavioral and molecular responses in the hypothalamus according to photoperiodic conditions.

Dantas-Ferreira RF, Dumont S, Gourmelen S, Cipolla-Neto J, Simonneaux V, Pévet P, Challet E - PLoS ONE (2015)

Food-anticipatory activity in a hamster exposed to a short photoperiod.Panel A: wheel-running activity; panel B: general cage activity. Each line represents 48 h, plotted in 5-min bins. The initial light-dark cycle (10 h of light, 14 h of darkness; full short photoperiod) is indicated by horizontal white and black bars. Zeitgeber time (ZT) 0 corresponds to lights on. Gray shaded areas indicate periods of darkness. Arrows on the right Y axis show the different photoperiodic conditions (Sk: skeleton long photoperiod, comprising 1-h light from ZT 0 to ZT 1 followed by 12-h dark, and then 1-h light from ZT 9 to ZT 10, and 14-h dark; Fu: full short photoperiod, comprising 10 h of light and 14 h of dark). During baseline, hamsters were fed ad libitum (AL). Green shaded areas show the daily 12-h period of food access during restricted feeding (RF), from midday (i.e., ZT 5) to ZT 17. Arrows on the left Y axis show the onset of food restriction. Arrows next to Sk_RF (early) and Sk_RF (late) on the right Y axis show the first and second periods of restricted feeding under Sk, respectively.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4430487&req=5

pone.0126519.g003: Food-anticipatory activity in a hamster exposed to a short photoperiod.Panel A: wheel-running activity; panel B: general cage activity. Each line represents 48 h, plotted in 5-min bins. The initial light-dark cycle (10 h of light, 14 h of darkness; full short photoperiod) is indicated by horizontal white and black bars. Zeitgeber time (ZT) 0 corresponds to lights on. Gray shaded areas indicate periods of darkness. Arrows on the right Y axis show the different photoperiodic conditions (Sk: skeleton long photoperiod, comprising 1-h light from ZT 0 to ZT 1 followed by 12-h dark, and then 1-h light from ZT 9 to ZT 10, and 14-h dark; Fu: full short photoperiod, comprising 10 h of light and 14 h of dark). During baseline, hamsters were fed ad libitum (AL). Green shaded areas show the daily 12-h period of food access during restricted feeding (RF), from midday (i.e., ZT 5) to ZT 17. Arrows on the left Y axis show the onset of food restriction. Arrows next to Sk_RF (early) and Sk_RF (late) on the right Y axis show the first and second periods of restricted feeding under Sk, respectively.
Mentions: Locomotor activity was assessed by both wheel-running activity and general cage activity (Figs 2 and 3).

Bottom Line: When food availability is restricted, animals adjust their behavior according to the timing of food access.During FAA under skeleton photoperiods, c-Fos expression was increased in the arcuate nuclei independently of the photoperiod, but differentially increased in the ventromedial and dorsomedial hypothalamic nuclei according to the photoperiod.FAA in general activity was hardly modulated by daytime light, but was reduced under SP.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurobiology of Rhythms, Institute of Cellular and Integrative Neurosciences, UPR 3212 CNRS, University of Strasbourg, Strasbourg, France; Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.

ABSTRACT
When food availability is restricted, animals adjust their behavior according to the timing of food access. Most rodents, such as rats and mice, and a wide number of other animals express before timed food access a bout of activity, defined as food-anticipatory activity (FAA). One notable exception amongst rodents is the Syrian hamster, a photoperiodic species that is not prone to express FAA. The present study was designed to understand the reasons for the low FAA in that species. First, we used both wheel-running activity and general cage activity to assess locomotor behavior. Second, the possible effects of photoperiod was tested by challenging hamsters with restricted feeding under long (LP) or short (SP) photoperiods. Third, because daytime light may inhibit voluntary activity, hamsters were also exposed to successive steps of full and skeleton photoperiods (two 1-h light pulses simulating dawn and dusk). When hamsters were exposed to skeleton photoperiods, not full photoperiod, they expressed FAA in the wheel independently of daylength, indicating that FAA in the wheel is masked by daytime light under full photoperiods. During FAA under skeleton photoperiods, c-Fos expression was increased in the arcuate nuclei independently of the photoperiod, but differentially increased in the ventromedial and dorsomedial hypothalamic nuclei according to the photoperiod. FAA in general activity was hardly modulated by daytime light, but was reduced under SP. Together, these findings show that food-restricted Syrian hamsters are not prone to display FAA under common laboratory conditions, because of the presence of light during daytime that suppresses FAA expression in the wheel.

No MeSH data available.


Related in: MedlinePlus