An Italian-Japanese research team has shown that neonicotinoid pesticides can cause autism-like symptoms in chicks. Possible similar risks for humans.
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Autism spectrum disorders (or autism) are linked to atypical neurodevelopment and manifest as social interaction deficits, verbal communication difficulties, and other conditions. The triggers are not yet understood, but exposure during pregnancy to various environmental chemicals – such as valproic acid (VPA) and pesticides that act on nicotinic acetylcholine receptors (nAChR) – would be considered as risk factors. Scientists have just discovered that chicks exposed to low doses of neonicotinoid pesticides – such as imidacloprid – develop symptoms similar to those of human autism; this suggests that these substances may potentially be involved in triggering the disease.
An international research team led by Japanese scientists from Hokkaido University’s Faculty of Science, who worked closely with colleagues, determined that neonicotinoid pesticides can cause symptoms similar to autism spectrum disorders in children. man in the chicks of the University of Tokyo and the Faculty of Pharmaceutical Sciences. from Teikyo University. The two Italian scientists Paola Sgadò and Giorgio Vallortigara from the Center for Mind/Brain Sciences at the University of Trento also took part in the study. The researchers, coordinated by Professor Toshiya Matsushima from the Department of Biology at Sapporo University, reached their conclusions following exposing fertilized chicken eggs to substances associated with blocking fetal movement. The interruption of such movements, according to experts, influences the development of biological movement preference (BM). Since among the early signs of autism spectrum disorders is a delayed preference for animate objects, such as biological movement, the study authors wanted to understand if influencing it with the aforementioned substances might cause autism-like symptoms. The researchers used chicks for the experiment because they develop a preference for biological movement like human infants, unlike mammalian animal models (such as rats and mice) which do not exhibit it spontaneously.
The researchers exposed the fertilized eggs to various substances such as ketamine, tubocurarine, methyllicaconitine and imidacloprid (IMI), all of which markedly reduced the preference for biological movement, without however affecting the formation of the memory of imprint (unlike valproic acid). Particularly significant has been the impact of the neonicotinoid pesticide imidacloprid, widely used in agriculture and also associated with the infamous hive depopulation syndrome, which since 2006 has led to the collapse of many bee colonies around the world. Imidacloprid was able to alter biological movement preference at concentrations as low as 1 ppm (part per million), so the study authors believe that neonicotinoids in the environment might also trigger a similar effect. in human infants if exposed during pregnancy.
Interestingly, as noted in a press release, feeding the chicks a drug known to reduce the severity of some cases of autism (bumetanide) restored the typical preference for organic movement. However, since there are significant neurobiological differences between humans and birds, researchers will need to conduct additional and thorough investigations for any confirmation of the case. Details of the research “Fetal blockade of nicotinic acetylcholine transmission causes autism-like impairment of biological movement preference in the neonatal chick” have been published in the scientific journal Cerebral Cortex.
