Adverse Effects of Neonicotinoids and Organophosphate insecticides on Cholinergic Mammalian Brain Development

<p>Increase of developmental disorders, such as autism spectrum disorders, (ASD), attention deficit/hyperactive disorders (ADHD) is serious problem in Japan. The cause of increase is mainly environmental for those with a genetic predisposition. Environmental factors include nurture, parental age, nutrition, infection, and so forth, and environmental chemicals are the most likely risk factors, because of their rapid increase in the past 70 years and the evidence-based various epidemiological and animal model studies. Especially, those data have shown that perinatal exposure to organophosphate pesticides (OP) have more risk for developmental disorders, through inhibition of cholinesterase. Cholinergic system is important for mammalian brain development. In addition to OP, our data showed that neonicotinoid insecticides (NEO) disrupt mammalian cholinergic synaptic transmission, through nicotinic acetylcholine receptor, and disturbed neurite extension. (Plos One,7,2012, IJERPH, 13,2016). Various reports have suggested neurodevelopmental toxicity of NEO (Environ Res, 187, 2020). In Japanese children and infant, OP and NEO have been highly detected in their urine (Environ Res,147,2016, Environ Int, 134,2020, Sci Total Environ, 750, 2021). Both of signal toxicity (J Toxicol Sci, 41, 2016) of OP and NEO may be one of causal factors of developmental disorders.</p>