“Bio-communication” Between Mother and Offspring: Lessons From Animals and New Perspectives for Brain Science

Physical exercise ameliorates memory impairment in offspring of old mice

For humans, maternal old age means the age of 35 or older at the time of childbirth. Maternal metabolism not only affects the cognitive function of the offspring, but also affects their physical and neurological development. This study aims to elucidate the effects of exercise training on spatial learning memory, neurogenesis, and apoptosis in the off-spring of old mice. Using mice, the offspring of old mothers showed impaired spatial learning memory, decreased brain-derived neurotrophic factor and postsynaptic density protein 95 levels, suppressed neurogenesis, and increased hippocampal apoptotic cell death. In contrast, the offspring of the old mothers had improved spatial learning memory, increased brain-derived neurotrophic factor and postsynaptic density protein 95 levels, increased neurogenesis, and decreased hippocampal apoptotic cell death when they received exercise training. The present results indicate that there is apparent spatial learning memory impairment among the offspring of old mothers, but by contrast, exercise can ameliorate spatial learning memory impairment. Exercise can be an effective countermeasure against memory decline in the offspring of old mothers.

Effects of Exercise Training during Advanced Maternal Age on the Cognitive Function of Offspring

Advanced maternal age (AMA) denotes an age of ≥35 years during the time of delivery. Maternal metabolism affects the offspring’s physical and neurological development as well as their cognitive function. This study aimed to elucidate the effects of exercise training among old female animals on the cognitive function, hippocampal neuroplasticity, mitochondrial function, and apoptosis in the offspring. We found that the offspring of mothers with AMA without exercise training had decreased spatial learning and memory, brain-derived neurotrophic factor (BDNF) and postsynaptic density protein 95 (PSD-95) protein levels, neurogenesis, and mitochondrial function, as well as hippocampal cell death. Contrastingly, offspring of mothers with AMA with exercise training showed improved spatial learning, memory, hippocampal neuroplasticity, and mitochondrial function. These findings indicate that despite the AMA, increasing fitness through exercise significantly contributes to a positive prenatal environment for fetuses. The maternal exercises augmented the hippocampal levels of BDNF, which prevents decreased cognitive function in the offspring of mothers with AMA.

Maternal High-Fat Diet Multigenerationally Impairs Hippocampal Synaptic Plasticity and Memory in Male Rat Offspring

As advances are made in the field of developmental origins of health and disease, there is an emphasis on long-term influence of maternal environmental factors on offspring health. Maternal high-fat diet (HFD) consumption has been suggested to exert detrimental effects on cognitive function in offspring, but whether HFD-dependent brain remodeling can be transmitted to the next generations is still unclear. This study tested the hypothesis that HFD consumption during rat pregnancy and lactation multigenerationally influences male offspring hippocampal synaptic plasticity and cognitive function. We observed that hippocampus-dependent learning and memory was impaired in 3 generations from HFD-fed maternal ancestors (referred as F1-F3), as assessed by novel object recognition and Morris water maze tests. Moreover, maternal HFD exposure also affected electrophysiological and ultrastructure measures of hippocampal synaptic plasticity across generations. We observed that intranasal insulin replacement partially rescued hippocampal synaptic plasticity and cognitive deficits in F3 rats, suggesting central insulin resistance may play an important role in maternal diet-induced neuroplasticity impairment. Furthermore, maternal HFD exposure enhanced the palmitoylation of GluA1 critically involved in long-term potentiation induction, while palmitoylation inhibitor 2-bromopalmitate counteracts GluA1 hyperpalmitoylation and partially abolishes the detrimental effects of maternal diet on learning and memory in F3 offspring. Importantly, maternal HFD-dependent GluA1 hyperpalmitoylation was reversed by insulin replacement. Taken together, our data suggest that maternal HFD exposure multigenerationally influences adult male offspring hippocampal synaptic plasticity and cognitive performance, and central insulin resistance may serve as the cross-talk between maternal diet and cognitive impairment across generations.

Physical exercise improves cognitive function by enhancing hippocampal neurogenesis and inhibiting apoptosis in male offspring born to obese mother

Maternal obesity induces hippocampal functional changes and leads to deficits in cognitive functions, such as learning and memory in offspring. We investigated the protective effects of physical exercise against cognitive function deficit in offspring born to obese mothers. Neurotrophic factors, neurogenesis, and apoptosis were analyzed in the hippocampus and dentate gyrus of offspring. Four-week-old female rats were fed a high-fat diet (HFD) for 20 weeks: 12 weeks prior to mating, and 8 weeks during pregnancy and breast-feeding. Male offspring rats were randomly divided into four groups: Control group (CON), exercise and control group (ECON), male offspring born to obese mother group (MOM), and exercise and MOM group (EMOM). In the exercise groups, treadmill exercise was performed 6 times per week for 4 weeks. Male offspring rats were subjected to the Morris water maze tests and step-down avoidance to assess spatial learning and memory, and short-term memory. The result showed that deficits in spatial learning and memory, and short-term memory in male offspring born to obese mothers was associated with decreases in brain-derived neurotrophic factor (BDNF) levels and neurogenesis, and an increase in apoptosis in the hippocampal dentate gyrus. Physical exercise improved spatial learning and memory, and short-term memory by enhancing BDNF levels and neurogenesis, and by inhibiting apoptosis in the hippocampal dentate gyrus of male offspring born to obese mothers. Our results suggest that physical exercise may be a preventive measure against or a treatment for cognitive function impairment.

Paternal physical exercise improves spatial learning ability by enhancing hippocampal neuroplasticity in male pups born from obese maternal rats

Maternal obesity exerts negative effects on cognitive function and behavior of the offspring. In the present study, we assessed the effects of paternal physical exercise on spatial learning ability in relation with hippocampal neuroplasticity in the rat pups born from the obese maternal rats. There were four experimental groups: paternal nonexercised male pups from normal maternal rats, paternal exercised male pups from normal maternal rats, paternal nonexercised male pups from obese maternal rats, and paternal exercised male pups from obese maternal rats. Normal diet was supplied for normal maternal rats and high-fat diet was supplied for obese maternal rats for a 12-week period until mating, and the same diet for each group continued throughout pregnancy and lactation period. Male rats in the exercising groups exercised for a 12-week period. Spatial learning ability was reduced in the male rat pups born from the obese maternal rats. Expressions of brain-derived neurotrophic factor (BDNF) and tyrosine kinase B receptor (TrkB) in the hippocampus were suppressed and cell proliferation and differentiation in the hippocampus were reduced in the male rat pups born from the obese maternal rats. Paternal treadmill exercise improved spatial learning ability, increased BDNF and TrkB expressions, and enhanced cell proliferation and differentiation in the male rat pups born from the obese maternal rats. It can be suggested that paternal exercise enhances hippocampal neuroplasticity and consequently improved spatial learning ability in the rat pups born from the obese maternal rats.

Maternal prepregnancy BMI and child cognition: a longitudinal cohort study

OBJECTIVE

To examine the association between maternal prepregnancy BMI and cognitive performance in children at 5 and 7 years of age.

METHODS

This is a secondary analysis of data from the Millennium Cohort Study, a prospective population based cohort of 19,517 children in the United Kingdom. Standardized cognitive assessments of children, involving components of the British Ability Scales, second edition and a number skills test, were performed at 5 and 7 years of age. Principal components analysis was used to identify a general cognitive ability factor (g) from individual test scores. Maternal prepregnancy BMI was retrospectively self-reported when children were 9 months old. Mixed-effects linear regression models were fitted, controlling for multiple socio-demographic factors, child's birth weight, child's BMI, maternal smoking, and maternal diabetes. Complete data were available for 11,025 children at 5 years, and 9882 children at 7 years.

RESULTS

Maternal prepregnancy BMI was negatively associated with children's cognitive performance (g) at age 5 (P = .0069) and age 7 (P < .0001). The overall effect size was modest: a 10-point increase in maternal BMI was associated with a decrease in cognitive performance of ~1/10th of an SD at age 7.

CONCLUSIONS

Maternal prepregnancy BMI is negatively associated with children's cognitive performance, even after adjusting for multiple socio-demographic confounders and children's BMI. The relationship appears to become stronger as children get older, although the overall effect size is modest. In utero fetal programming or residual confounding may explain these findings.