Altered Expression of Nicotinic Receptors in Perinatal Life Related to Prenatal Exposure to Toxics—An Overview of the Research Carried Out on This Topic at the “Lino Rossi” Research Center of the Milan University

Abstract

The article aims to underline the impact of nicotine and pesticides on neuronal α 7-nicotinic acetylcholine receptors expression in brainstem regions receiving cholinergic projections, given their fundamental role during the neuronal development. The in-depth histopathological/immunohistochemical examination of the autonomic nervous system performed at the “Lino Rossi” Research Center of the Milan University on a wide group of sudden unexpected fetal and infant deaths, highlighted the frequent hypodevelopment of brainstem structures checking the vital functions associated to altered expression of α 7-nicotinic acetylcholine receptors and smoke absorption in pregnancy. A dysregulation of the catecholamine system was also observed in the cerebellar cortex of the same cases. However, in a not negligible percentage of sudden deaths with altered expression of α 7-nicotinic receptors, the mothers never smoked but lived in rural areas. Specific analytical procedures showed the presence of agricultural pesticides in cerebral cortex samples of these victims. Therefore, it is possible to believe that the exposition to pesticides during pregnancy can produce the same harmful effects as nicotine on the nicotinic acetylcholine receptors. Moreover, alterations of α 7-nicotinic acetylcholine receptors receptor expression were also detected in the lungs of many sudden perinatal death victims, allowing to consider even these findings as possible consequence of maternal exposure to toxic factors.