Malnutrition/exercise interaction in the rat mother-pup dyad: a behavioral and electrophysiological analysis

Maternal protein malnutrition alters brain functioning, impairing fetal development. Physical exercise during gestation benefits the fetal organism from maternal adaptive changes that may be neuroprotective. This study evaluated the effect of a low-protein diet associated with maternal voluntary physical activity (VPA) on rats' behavioral and brain electrophysiological parameters in the mother-pup dyad.

Female Wistar rats (n = 40) performed VPA on running wheels during a 30-day pre-mating period. Daily running distance, activity duration, and caloric expenditure enabled us to classify the dams as sedentary or exercised. During pregnancy, half of the mothers were fed a low-protein diet (8% protein from casein), and the other half was fed a standard diet with 17% protein from casein. After lactation, when the mothers reached 150-160 days and the pups aged 30-35, animals were tested to evaluate anxiety-like behaviors in the open field and the elevated plus maze, and assess object recognition memory in the open field apparatus. At 160-170 days of life (mothers) and 35-45 days (pups), the animals were subjected to a recording session of the excitability-related phenomenon known as cortical spreading depression (CSD).

In the mother-pup dyad, malnutrition accelerated CSD, increased anxiety-like behavior, and impaired memory, whereas VPA produced the opposite effects. The greater impact of exercise was observed among the malnourished animals.

Our results provide important evidence about the beneficial modulating role of perinatal VPA (before, during and up to 14 days after pregnancy) in reprograming the effects of protein malnutrition on the central nervous system.