Impact of Maternal Road Traffic Noise Exposure on Hippocampal Spatial Memory and Neurogenesis of Sprague Dawley Offspring: Therapeutic Effects of Edaravone, Melatonin, and Enriched Environments.

Abstract

Introduction: Mental problems are associated with early neonatal and in utero exposure to maternal stress. With established negative impacts on mental health and cognitive function, road traffic noise (RTN) has emerged as a ubiquitous environmental stressor. In this work, we have examined the effects of maternal exposure to RTN on the development of neurogenesis and spatial memory in the hippocampus (HC) of offspring and investigated possible strategies for mitigating these effects.

Method: During the prenatal maturation stage, female Sprague Dawley (SD) rats that were determined to be pregnant were exposed chronically to 100 dB SPL (sound pressure level) RTN for six hours per day. The Morris water maze and elevated plus maze tests were used to evaluate the neurobehavioral performances of the offspring. The oxidative stress and neurogenesis in the HC were evaluated using 2% 2,3,5-triphenyl tetrazolium chloride staining, HC histopathology, and biochemical methods (SOD: superoxide dismutase, GSH: glutathione, CAT: catalase, as well as TBARS: thiobarbituric acid reactive substance, MPO: myeloperoxidase, and AChE: acetylcholinesterase), respectively. Additionally, we looked at the potential therapeutic benefits of melatonin, edaravone, and an enriched environment.

Result: The results of our investigation showed that maternal exposure to 100 dB SPL RTN considerably reduced the offspring's spatial memory and caused distress. The biochemical estimation of HC tissue supernatant revealed a considerable increase in MPO, AChE, and TBARS levels and a marked reduction in SOD, CAT, and GSH levels. However, there were notable protective effects against these unfavorable outcomes due to the administration of melatonin and edaravone, as well as from being exposed to an enriched environment.

Discussion: In our study, prenatal exposure to 100 dB SPL RTN caused oxidative stress, which caused neurodegeneration, as well as decreased spatial memory and induced anxiety, being consistent with previous findings. In particular, compared to offspring of the 100 dB SPL RTNexposed group, offspring of the maternally treated EDV and MLT combination groups showed superior spatial memory function, reduced anxiety, and increased neurogenesis.

Conclusion: The findings of our study have offered promising pathways for public health policies and urban planning concerns, as well as useful insights into the development of tailored therapies to safeguard against the cognitive and neurological repercussions of maternal RTN exposure.