Rats' activity: influence of light-dark cycle, food presentation and deprivation.
D000818:Animals; D003216:Conditioning, Operant; D003623:Dark Adaptation; D003624:Darkness; D004777:Environment; D005247:Feeding Behavior; D005508:Food Deprivation; D008027:Light; D008297:Male; D009043:Motor Activity; D051381:Rats; D012055:Reinforcement Schedule; D012054:Reinforcement, Psychology; D013997:Time Factors