Endocrine Abstracts

Long-term diabetes is associated with accelerated ageing of the brain as evidence by impairment of cognitive function as well as motor performance. The aim of this study was to investigate the effects of voluntary daily exercise and environmental enrichment on spatial memory and learning as well as motor coordination and learning, in diabetic mice. Briefly, BALB/C mice (20–25 g) received 55 mg/kg streptozotocin i.p. daily for 5 days. Diabetes was confirmed by measurement of random blood glucose. Diabetic mice were randomly assigned to one of the following groups for 12 weeks duration: i) social isolation; ii) environmental enrichment; iii) environmental enrichment and voluntary daily exercise. A 4th group consisted of normal controls with environmental enrichment and voluntary daily exercise. At the end of 12 weeks blood glucose measurements were repeated and animals were assessed by the Morris Water Maze and the Rotarod for cognitive and motor performance respectively. Exercise per se did not have a significant additional benefit on learning and memory compared to environmental enrichment alone, in diabetic mice. In diabetics, motor learning was impaired with isolation but enhanced with environmetal enrichment and exercise. After week 12 there were no differences in blood glucose when comparing between diabetic groups. In conclusion, environmental enrichment confers significant benefits on cognition and motor performance and the latter effect can be enhanced by adding exercise. The effects of enrichment on motor learning are worthy of further investigation as regards the mechanism and whether or not such benefits would translate to other motor activities.