Donna L Korol | PubMed Health

PubMed2002

Estrogen-induced changes in place and response learning in young adult female rats.

Many findings suggest that changes in circulating estrogen levels influence cognition, in some cases impairing performance and in others enhancing performance. One interpretation of these mixed effects is that estrogen biases the strategy used to solve a task. To test this idea, young adult female rats, ovariectomized for 21 days, were trained after acute hormone or control treatment in 2 very similar tasks with different cognitive requirements. One task required place learning and the other response learning. Rats given two 10-microg injections of estradiol 48 and 24 hr before training learned the place task significantly faster than did rats without estradiol. Conversely, rats without estradiol performed better on the response task than did rats with replacement. These data suggest that the cognitive actions of estrogen may be task-specific by modulating the relative contribution of different learning and memory systems.

Aging↗

PubMed2002

Enhancing cognitive function across the life span.

Glucose administration regulates many neural and behavioral processes in rodents, including learning and memory. Given the important role of glucose in brain function and the safety of glucose as a treatment, we have investigated the effects of glucose administration in humans of different ages. In previous work, we examined the effects of early-morning glucose consumption on cognitive functions in elderly individuals. In this population, glucose enhanced performance on specific measures, particularly on those tasks where mild age-related deficits appear (e.g., verbal declarative memory). Interestingly, glucose failed to enhance cognitive functions in young adults. Our recent work has examined three issues related to glucose enhancement of cognition: First, is glucose effective only in reversing impairments or can it also facilitate performance in highly functioning individuals? Second, are glucose effects dependent either on time of day or on interactions with other meals? Third, are typical breakfast foods as effective as glucose in enhancing cognitive performance? Our findings suggest that glucose can improve memory in highly functioning populations as it does in populations with deficits. However, enhancement by glucose may require sufficient levels of task difficulty and of blood glucose. In addition, like glucose, early morning consumption of cereal can improve performance on some cognitive tests. These results have important implications for the nature of glucose facilitation of memory and for the role of dietary factors in performance of many daily activities.

Aging↗