Brief access to sucrose engages food-entrainable rhythms in food-deprived rats.
Two studies examined whether brief access to sucrose solutions engages food-entrainable rhythms when pitted against a light-dark cycle. In Experiment 1, 32% sucrose was given once daily for 5-6 min at Zeitgeber Time 4 (ZT 4) for 17-18 days to 8 food-deprived and 8 ad-lib-fed rats. Chow was provided at ZT 16. Temperature, wheel running, activity, and corticosterone (B) anticipated sucrose only in food-deprived rats. Ad-lib rats were similar to controls. In Experiment 2, 32% sucrose was presented at ZT 4 for 5 or 10 min for 17 days to food-deprived rats. Chow was given at ZT 12. Exogenous cues were minimized. Both groups showed anticipation of sucrose, whereas room controls did not. After a shift to 4% sucrose for 8 days, the 10-min group showed signs of damping of these rhythms, whereas the 5-min group did not. Data indicated that brief access to sucrose engages food-entrainable rhythms in food-deprived rats.
D000704:Analysis of Variance; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001835:Body Weight / Q000187:drug effects / Q000502:physiology; D002940:Circadian Rhythm; D003345:Corticosterone / Q000032:analysis / Q000097:blood; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000502:physiology; D002149:Energy Intake; D005108:Extinction, Psychological; D005230:Fatty Acids, Nonesterified / Q000032:analysis / Q000097:blood; D005247:Feeding Behavior / Q000502:physiology*; D005502:Food; D005508:Food Deprivation; D007328:Insulin / Q000032:analysis / Q000097:blood; D020738:Leptin / Q000032:analysis / Q000097:blood; D008297:Male; D009043:Motor Activity; D051381:Rats; D017207:Rats, Sprague-Dawley; D013395:Sucrose / Q000494:pharmacology*; D013696:Temperature; D013739:Testosterone / Q000032:analysis / Q000097:blood; D013997:Time Factors; D014280:Triglycerides / Q000032:analysis / Q000097:blood
D001786:Blood Glucose; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D020738:Leptin; D014280:Triglycerides; D013739:Testosterone; D013395:Sucrose; D003345:Corticosterone