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Although exogenous D-serine has been applied as a neural regulatory intervention in many studies, the role played by D-serine in hippocampal injuries caused by lead exposure remains poorly understood. Rat models of chronic lead exposure were established through the administration of 0.05% lead acetate for 8 weeks. Simultaneously, rats were administered 30 or 60 mg/kg D-serine, intraperitoneally, twice a day. Our results showed that D-serine treatment shortened the escape latency from the Morris water maze, increased the number of times that mice crossed the original platform location, and alleviated the pathological damage experienced by hippocampal neurons in response to lead exposure. Although D-serine administration did not increase the expression levels of the N-methyl-D-aspartate receptor subtype 2B (NR2B) in the hippocampi of lead-exposed rats, 60 mg/kg D-serine treatment restored the expression levels of NR2A, which are reduced by lead exposure. These findings suggested that D-serine can alleviate learning and memory impairments induced by lead exposure and that the underlying mechanism is associated with the increased expression of NR2A in the hippocampus. This study was approved by the Animal Ethics Committee of North China University of Science and Technology, China (approval No. LX2018155) on December 21, 2018.

With the introduction of the global brain science program, the brain science and cognitive science are listed as one of the important research areas in China, the goal of which is to understand the function of the brain. In the human brain plan, the neurodegeneration and neurodevelopment in diseases and aging are one of the key areas of concern. However, lead is an environmental heavy metal neurotoxin, which can cause neurodegenerative diseases and affect brain health. At present, the mechanism of the lead-induced nervous system damage mainly focuses on the damage of lead to neurons, while the researches related to the repair of damaged nerve cells induced by the lead exposure have not been reported. The Transcriptome sequencing technology is direct detection of transcripts by the deep sequencing technology, which can more accurately measure the expression of transcripts, and is an inevitable link between genomic genetic information and the proteome of biological functions. In addition, the regulation of the transcription level is the most important regulation mode of organisms. Based on the characteristics of neurogenesis for nerve repair, the current study applied transcriptional sequencing technology to screen the differentially expressed genes in the choroid plexus of rats and to explore the changes in the expression of neurotrophic factors regulating neurogenesis in the choroid plexus of the lead-exposed rats. The results showed that the differentially expressed genes on choroid plexus of the lead exposed rats were related to neurogenesis. In the process of neurogenesis, the expression of nutritive and growth-promoting factors IGF1, EGFr, IGF1r, EGFr1, VEGFα , and TGFβ2 decreased, which suggested that these cytokines may be involved in the process of lead exposure neurogenesis, which needs further experimental verification. The findings of this study provide a new target for the mechanism research and prevention and control measures of brain nerve injury caused by the lead exposure.