AN INVESTIGATION OF GLUCOSE EFFECTS ON LEARNING AND MEMORY IMPAIRMENTS INDUCED BY HIGH-FAT DIETS AND ENVIRONMENTAL-FACTORS

We previously demonstrated that feeding rats high fat diets impairs pe rformance on learning and memory tests. This study examined the combin ed effects of environmental factors and diet on cognition to determine if glucose administration could enhance performance adversely affecte d by these factors. Subjects were tested on a variable interval delaye d alternation task which measures learning and memory functions that d ifferentially involve specific brain regions. The results confirmed th e negative effects of high fat diets and showed that environmental enr ichment improved acquisition of the basic habit. By comparison, glucos e selectively enhanced trial-specific memory performance at longer del ays. We conclude that high fat diets generally disrupt cognitive funct ion. The enriched environment reduced learning impairment associated w ith frontal lobe function whereas glucose mediated its beneficial effe cts on hippocampus-related memory function.