For omnivores to determine whether an unfamiliar item is an appropriate food, they could rely on personal information from sampling it themselves or rely on less risky observation of whether other individuals eat the ...For omnivores to determine whether an unfamiliar item is an appropriate food, they could rely on personal information from sampling it themselves or rely on less risky observation of whether other individuals eat the item. Availability of information about food from social companions in group-living species is one of the benefits of group life. Adults of solitary-living species, however, seem typically less likely to rely on social information about food choice. If an individual faced a nutritional deficit, it would seem to increase the value of public information. This study addresses whether dietary restriction from certain nutrients (sodium, potassium, protein, carbohydrates) affects reliance on information about food from conspecifics. Without nutrient restriction, group-living Norway rats (Rattus norvegicus) preferred the diet that they smelled on the breath of a conspecific demonstrator, but solitary-living Syrian hamsters (Mesocricetus auratus) avoided it. Protein restriction yielded similar results as measured one hour into a diet choice test. Potassium restriction, however, reversed the pattern: rats avoided the demonstrator’s diet but hamsters preferred it. Clearly, the valence of social information depended on the nutrient from which individuals were restricted and the species under study. This could be related to the contrasting social organization that members of each species generate. Neither species relied on social information about the availability of a nutrient from which they were restricted if they could taste that nutrient for themselves (sodium, carbohydrates).展开更多
Obesity is linked to poorer cognitive performance, both of which may result from eating high-fat foods during development. In the present study, pre-and periadolescent (postnatal days 21 to 40) male rats were fed high...Obesity is linked to poorer cognitive performance, both of which may result from eating high-fat foods during development. In the present study, pre-and periadolescent (postnatal days 21 to 40) male rats were fed high fat (HF), high sugar (HS), or rodent chow (Chow) diets. After conditioning for 16 days with either Cheetos? (high-fat) or Froot Loops? (high-sugar) unconditioned stimuli (US) on one side of a conditioned place preference (CPP) apparatus, rats were tested on postnatal day 61 for a place preference. Chow rats preferred the US-paired side, but HF rats showed no preference. HS rats preferred the side paired with Cheetos? but not with Froot Loops?. In spite of these deficits, object recognition, a nonassociative learning task, was not impaired. These results show mixed support for the specificity hypothesis, which predicts that CPP deficits will be nutrient-specific. The results show for the first time that eating a HS diet leads to a nutrient-specific CPP deficit (for HS foods), whereas eating a HF diet leads to a general CPP deficit (for HS and HF foods).展开更多
文摘For omnivores to determine whether an unfamiliar item is an appropriate food, they could rely on personal information from sampling it themselves or rely on less risky observation of whether other individuals eat the item. Availability of information about food from social companions in group-living species is one of the benefits of group life. Adults of solitary-living species, however, seem typically less likely to rely on social information about food choice. If an individual faced a nutritional deficit, it would seem to increase the value of public information. This study addresses whether dietary restriction from certain nutrients (sodium, potassium, protein, carbohydrates) affects reliance on information about food from conspecifics. Without nutrient restriction, group-living Norway rats (Rattus norvegicus) preferred the diet that they smelled on the breath of a conspecific demonstrator, but solitary-living Syrian hamsters (Mesocricetus auratus) avoided it. Protein restriction yielded similar results as measured one hour into a diet choice test. Potassium restriction, however, reversed the pattern: rats avoided the demonstrator’s diet but hamsters preferred it. Clearly, the valence of social information depended on the nutrient from which individuals were restricted and the species under study. This could be related to the contrasting social organization that members of each species generate. Neither species relied on social information about the availability of a nutrient from which they were restricted if they could taste that nutrient for themselves (sodium, carbohydrates).
文摘Obesity is linked to poorer cognitive performance, both of which may result from eating high-fat foods during development. In the present study, pre-and periadolescent (postnatal days 21 to 40) male rats were fed high fat (HF), high sugar (HS), or rodent chow (Chow) diets. After conditioning for 16 days with either Cheetos? (high-fat) or Froot Loops? (high-sugar) unconditioned stimuli (US) on one side of a conditioned place preference (CPP) apparatus, rats were tested on postnatal day 61 for a place preference. Chow rats preferred the US-paired side, but HF rats showed no preference. HS rats preferred the side paired with Cheetos? but not with Froot Loops?. In spite of these deficits, object recognition, a nonassociative learning task, was not impaired. These results show mixed support for the specificity hypothesis, which predicts that CPP deficits will be nutrient-specific. The results show for the first time that eating a HS diet leads to a nutrient-specific CPP deficit (for HS foods), whereas eating a HF diet leads to a general CPP deficit (for HS and HF foods).
