title: Long-term dietary restriction causes negative effects on cognitive functions in rats.
abstract: Long-term dietary restriction is reported to increase life span and improve age-related cognitive deficits. The present study shows that the restriction increases the life span of rats but decreases their cognitive ability. Thirty-two rats were divided into restricted and ad lib feeding groups at 2.5 months of age. The restricted rats were kept at a weight of 280g. The restricted rats were poor in performing the Morris water maze task at 7-12 months. At 17-18 months, they were poor in performing the delayed matching-to-place task. At 24-27 months, the surviving 13 restricted and 5 ad lib rats performed the spatial discrimination task. The restricted rats were also poor in performing this task. Injection of glucose prior to the discrimination task improved their performance to the level of the ad lib rats. These results suggest that dietary restriction is beneficial for longevity but has negative effects on the performance of cognitive tasks, and that the cause of the negative effects may be a reduced availability of glucose in the food-restricted aged rats.
authors.affiliation: Department of Psychology, Doshisha University, Kyoto 602-8580, Japan. yanai@psychology.doshisha.ac.jp
authors.forename: Shuichi
authors.initials: S
authors.lastname: Yanai
authors.forename: Yoko
authors.initials: Y
authors.lastname: Okaichi
authors.forename: Hiroshige
authors.initials: H
authors.lastname: Okaichi
mesh_terms: D000375:Aging / Q000378:metabolism; D000818:Animals; D001786:Blood Glucose / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D031204:Caloric Restriction / Q000009:adverse effects*; D003072:Cognition Disorders / Q000209:etiology* / Q000378:metabolism* / Q000503:physiopathology; D004193:Discrimination Learning / Q000187:drug effects / Q000502:physiology; D005508:Food Deprivation / Q000502:physiology*; D005947:Glucose / Q000172:deficiency / Q000494:pharmacology; D008136:Longevity / Q000502:physiology; D008297:Male; D018782:Maze Learning; D008569:Memory Disorders / Q000209:etiology* / Q000378:metabolism* / Q000503:physiopathology; D051381:Rats; D017208:Rats, Wistar
chemical_list: D001786:Blood Glucose; D005947:Glucose