Treadmill exercise improves spatial learning ability by increasing cell proliferation in offspring born to maternal rats receiving stress during pregnancy

Maternal Treadmill Exercise and Zinc Supplementation Alleviate Prenatal Stress-Induced Cognitive Deficits and Restore Neurological Biomarkers in Offspring: A Study on Male Rats Aged 30 and 90 Days

The detrimental effects of prenatal stress (PS) on offspring's neurological and behavioral outcomes are well documented. However, strategies to mitigate these effects are underexplored. This study examines whether prenatal zinc supplementation and treadmill exercise can modulate PS-induced cognitive impairments and neurobiological markers in young and adult male rat offspring, leveraging the established neuroprotective potential of both physical activity and zinc. Pregnant rats were divided into five groups: control, stress, stress + exercise, stress + zinc, and stress + exercise + zinc, with all rats except the control group subjected to restraint stress (gestational days 15-19). Pregnant rats in the exercise groups underwent forced exercise, whereas those in the zinc groups received oral zinc sulfate throughout the pregnancy. At postnatal days 30 and 90, the cognitive function of male offspring was evaluated using the Morris water maze (MWM) test, and the hippocampal gene expression levels of caspase-3, brain-derived neurotrophic factor (BDNF), and glial fibrillary acidic protein (GFAP) were measured using reverse transcription-polymerase chain reaction (RT-PCR). PS impaired cognitive functions, increased caspase-3 expression, and decreased BDNF and GFAP expression levels in adult rats. Prenatal exercise was found to mitigate PS-induced cognitive deficits primarily through enhancing GFAP expression, whereas prenatal zinc improved PS-induced cognitive impairments mainly through reduced caspase-3 and increased BDNF expression. The combined effect of exercise and zinc was not additive on cognitive functions and biomarkers. Physical activity may alleviate PS-induced cognitive deficits by modulating astrocytic factors, whereas zinc may exert its effects by inhibiting apoptosis via a BDNF-dependent pathway. Further targeted research is necessary to confirm these relationships.

Spontaneous running wheel exercise during pregnancy prevents later neonatal-anoxia-induced somatic and neurodevelopmental alterations

Introduction

About 15-20 % of babies that suffer perinatal asphyxia die and around 25 % of the survivors exhibit permanent neural outcomes. Minimization of this global health problem has been warranted. This study investigated if the offspring of pregnant female rats allowed to spontaneously exercise on running wheels along a 11-day pregnancy period were protected for somatic and neurodevelopmental disturbs that usually follow neonatal anoxia.

Methods

spontaneous exercise was applied to female rats which were housed in cages allowing free access to running wheels along a 11-day pregnancy period. Their offspring were submitted to anoxia 24-36 h after birth. Somatic and sensory-motor development of the pups were recorded until postnatal day 21 (P21). Myelin basic protein (MBP)-stained areas of sensory and motor cortices were measured at P21. Neuronal nuclei (NeuN)-immunopositive cells and synapsin-I levels in hippocampal formation were estimated at P21 and P75.

Results

gestational exercise and / or neonatal anoxia increased the weight and the size of the pups. In addition, gestational exercise accelerated somatic and sensory-motor development of the pups and protected them against neonatal-anoxia-induced delay in development. Further, neonatal anoxia reduced MBP stained area in the secondary motor cortex and decreased hippocampal neuronal estimates and synapsin-I levels at P21; gestational exercise prevented these effects. Therefore, spontaneous exercise along pregnancy is a valuable strategy to prevent neonatal-anoxia-induced disturbs in the offspring.

Conclusion

spontaneous gestational running wheel exercise protects against neonatal anoxia-induced disturbs in the offspring, including (1) physical and neurobehavioral developmental impairments, and (2) hippocampal and cortical changes. Thus, spontaneous exercise during pregnancy may represent a valuable strategy to prevent disturbs which usually follow neonatal anoxia.

The role of enriched environment in neural development and repair

In addition to genetic information, environmental factors play an important role in the structure and function of nervous system and the occurrence and development of some nervous system diseases. Enriched environment (EE) can not only promote normal neural development through enhancing neuroplasticity but also play a nerve repair role in restoring functional activities during CNS injury by morphological and cellular and molecular adaptations in the brain. Different stages of development after birth respond to the environment to varying degrees. Therefore, we systematically review the pro-developmental and anti-stress value of EE during pregnancy, pre-weaning, and “adolescence” and analyze the difference in the effects of EE and its sub-components, especially with physical exercise. In our exploration of potential mechanisms that promote neurodevelopment, we have found that not all sub-components exert maximum value throughout the developmental phase, such as animals that do not respond to physical activity before weaning, and that EE is not superior to its sub-components in all respects. EE affects the developing and adult brain, resulting in some neuroplastic changes in the microscopic and macroscopic anatomy, finally contributing to enhanced learning and memory capacity. These positive promoting influences are particularly prominent regarding neural repair after neurobiological disorders. Taking cerebral ischemia as an example, we analyzed the molecular mediators of EE promoting repair from various dimensions. We found that EE does not always lead to positive effects on nerve repair, such as infarct size. In view of the classic issues such as standardization and relativity of EE have been thoroughly discussed, we finally focus on analyzing the essentiality of the time window of EE action and clinical translation in order to devote to the future research direction of EE and rapid and reasonable clinical application.