Environmental Factors and Limbic Vulnerability in Childhood Autism

Abstract

Abstract:The rise in prevalence of autism spectrum disorders (ASD) is suggestive of a new etiology. Diagnostic substitution alone is unlikely to account for the increase, while genetic association with detoxification gene alleles points to an environmental contribution. Subtle structural anomalies in the ASD brain are widespread but limbic damage seems important for the development of behaviors diagnostic of ASD. The limbic brain is especially susceptible to environmental challenge: internal sensing, physiological feedback and neuroinflammatory processes may underlie this sensitivity to insult. Primary damage leading to ASD in later life is likely to take place in utero and/or in the immediate postnatal period. Despite evidence of heavy metal involvement, a causal connection may not yet be concluded because subjects exposed to metals tend to be exposed to other environmental agents. Because maternal minerals and lipids are supplied to the unborn child, historic toxic exposure of the mother may be pivotal. A two-hit combination of genetic susceptibility and environmental challenge is argued to underlie the rise in ASD.

Central Causation of Autism/ASDs via Excessive [Ca2+]i Impacting Six Mechanisms Controlling Synaptogenesis during the Perinatal Period: The Role of Electromagnetic Fields and Chemicals and the NO/ONOO(-) Cycle, as Well as Specific Mutations

“…A number of individual scientists and research groups have suggested that increased autism/ASD incidence is associated with, and may be caused by, electromagnetic field (EMF) exposure [5,[93][94][95][96][97][98][99][100][101][102][103][104]. These are based on both correlations between increased ASD incidence and increased EMF exposures, and other types of evidence.…”

“…Each of the five human epidemiological studies cited here provide evidence in support of the view that EMF exposure may have a role in causing the autism epidemic. What is surprising, however, is that despite widespread concern about a possible causal link between EMF and autism/ASDs [5,[93][94][95][96][97][98][99][100][101][102][103][104] and the widespread concern about the autism/ASD epidemic, there have been few human epidemiological studies.…”

Autism‐relevant social abnormalities in mice exposed perinatally to extremely low frequency electromagnetic fields

“…This potentially implicates an environmental factor, which remains unidentified. Many injurious events during gestation and perinatal periods have been recognized as risk factors for developing ASD (Lathe, 2008).…”

“…The increased exposure to EMF is possibly one of the most dramatic and progressively escalating changes humans have had, in terms of environmental exposure, in the last few decades. Several papers have been published to demonstrate the plausibility of a causal link between the increased exposure to electromagnetism and the rise in the incidence of ASD (Kane, 2004;Lathe, 2008;Mariea and Carlo, 2007). A large number of studies have demonstrated that ELF EMF can have some biological (Giudice et al, 2007;Salehi et al, 2012;Tasset et al, 2012) and biochemical effects (He et al, 2013;Sadeghipour et al, 2012;Ulku et al, 2011), as well as effects on the behavior (Al-Maliki and Al-Rawi, 1992;Lai et al, 1998;Seppia et al, 2003;Sienkiewicz et al, 1998) and brain function (Choleris et al, 2001;Reyes-Guerrero et al, 2006;Sakhnini et al, 2012;Vázquez-Garcı ′ a et al, 2004) of rodents.…”