Neural and behavioral epigenetics; what it is, and what is hype

Abstract

The ability to examine epigenetic mechanisms in the brain has become readily available over the last 20 years. This has led to an explosion of research and interest in neural and behavioral epigenetics. Of particular interest to researchers, and indeed the lay public, is the possibility that epigenetic processes, such as changes in DNA-methylation and histone modification, may provide a biochemical record of environmental effects. This has led to some fascinating insights into how molecular changes in the brain can control behavior. However, some of this research has also attracted controversy and, as is dealt with here, some overblown claims. This latter problem is partly linked to the shifting sands of what is defined as 'epigenetics'. In this review, I provide an overview of what exactly epigenetics is, and what is hype, with the aim of opening up a debate as to how this exciting field moves forward.

Identification, Evaluation, and Management of Children With Autism Spectrum Disorder

“…Some genetic disorders associated with ASD (eg, Rett syndrome; CHARGE syndrome; 15q duplication; Angelman syndrome; and fragile X syndrome), involve genes that either encode epigenetic regulators or are sensitive to alterations in their epigenetic regulation. 223,224 Because epigenetic modifications can be influenced by environmental factors, such as prenatal maternal exposures and postnatal experience, they represent 1 interface between genes and environment. However, epigenetic modifications are not the only mechanisms by which gene expression is regulated, and epigenetics should not be conflated with the broader category of environmental effects.…”

“…However, epigenetic modifications are not the only mechanisms by which gene expression is regulated, and epigenetics should not be conflated with the broader category of environmental effects. 223,225 Currently, the evidence that alteration of gene expression by environmental factors plays a causal role in ASD is very limited. [223][224][225][226][227][228] Investigation of the role of epigenetic and other nongenetic modifications that alter gene activity without changing the DNA sequence is an active area of etiologic research in ASD.…”

Infant peripheral blood repetitive element hypomethylation associated with antiretroviral therapyin utero

“…Epigenetic changes may play an important role as mediators of the effects of the intrauterine environment on long-term health outcomes in offspring, including neurodevelopmental deficits, behavior, metabolic disorders, and obesity. [14][15][16][17][18][19][20][21][22] Epigenetic modifications are broadly defined as the mitotically heritable chemical or structural changes to DNA, which are involved in the regulation of gene expression without alteration of the underlying DNA sequence. The most widely studied of the epigenetic modifications is DNA methylation.…”

Progress With Nonhuman Animal Models of Addiction

“…We have also bred animals to display traits we believe to represent different addiction risks or symptoms (Noronha et al, 2014). Animal studies have recently shown us that JeanBaptiste Lamarck (1744-1829) was not entirely incorrect and that certain so-called epigenetic biochemical modifications of the genome caused by experience can be transmitted in the germ line to future generations (Isles, 2015). This has laid the final nails in the coffin of Genes versus Environment as mutually exclusive sources of generational influence-genes and environment interact in many ways and at all levels of analysis.…”