Voluntary exercise rescues deficits in spatial memory and long-term potentiation in prenatal ethanol-exposed male rats

Prenatal ethanol exposure can lead to long-lasting impairments in the ability to process spatial information in rats, as well as produce long-lasting deficits in the ability of animals to exhibit long-term potentiation, a biological model of learning and memory processing. Conversely, we have recently shown that both spatial memory and long-term potentiation can be enhanced in animals that are given access to a running wheel in their home cage. In the present study, Sprague-Dawley rat dams were given one of three diets throughout gestation: (i) a liquid diet containing ethanol (35.5% ethanol-derived calories); (ii) a liquid diet, isocaloric to the ethanol diet, but with maltose-dextrin substituting for the ethanol derived calories and (iii) an ad libitum diet of standard rat chow. At weaning (28 days) animals were housed individually in either a standard rat cage, or a cage that contained a running wheel. Adult offspring were tested on a two trial version of the Morris water maze beginning at postnatal day 60, for five consecutive days. Following this, the capacity of the perforant path to dentate gyrus pathway to sustain long-term potentiation was examined in these animals using theta-patterned conditioning stimuli. Our results demonstrate that prenatal ethanol exposure can produce pronounced deficits in both spatial memory and long-term potentiation, but that allowing animal's access to voluntary exercise can attenuate these deficits to the point that those exposed to ethanol prenatally can no longer be differentiated from control animals. These findings indicate that voluntary exercise may have therapeutic benefits for individuals that have undergone prenatal ethanol exposure.