Environmental factors, brain development, and intelligence in adulthood

Abstract

frequent in individuals born during the 4 months identified than at other times.Consideration of the percentage decrease in cognitive ability in a general population may be a powerful way of indentifying new causes of abnormal brain development. Indeed, with this method, it is possible to include large numbers of subjects systematically, improving confidence intervals.What mechanism is responsible of the observed effect? This point is carefully discussed by the authors. One possibility is mother-to-child transmission of the virus, as for rubella, CMV, varicella-zoster virus, or human immunodeficiency virus-1 infection, in a small percentage of infected women (influenced by the specific virus and the intensity of viremia, the socalled "viral load"). As for other viruses, following flu pandemics, increases in spontaneous abortions and brain malformations have been described. However, the relatively small decrease in IQ described here in otherwise apparently normal individuals seems less consistent with direct viral replication in the fetal brain as the underlying cause. Instead, it suggests a role for indirect factors linked to the maternal illness (including soluble factors of inflammation and the consequences of transient breathing or eating difficulties in the mother) early in gestation.

Congenital LCMV virus

“…Furthermore, the role that the immune response plays in inducing brain disease after LCMV infection is an important research area because it is applicable to a broad range of pathogens and inflammatory insults. Activation of the immune system during pregnancy has been associated with many developmental disorders such as low IQ, autism, and schizophrenia[239][240][241][242][243][244]. As mentioned in the intro, Erickson et.…”