The primary causes of individual differences in DNA methylation are environmental factors

This 2015 Canadian human study by McGill researchers found: “Differential methylation is primarily non-genetic in origin, with non-shared environment accounting for most of the variance. These non-genetic effects are mainly tissue-specific. The full scope of environmental variation remains underappreciated.” The researchers developed their findings using adipose and blood samples from monozygotic and dizygotic twins in … Continue reading The primary causes of individual differences in DNA methylation are environmental factors

If research treats “Preexisting individual differences” as a black box, how can it find causes for stress and depression?

This 2014 research studied both humans and rodents to provide further evidence on the physiology of defeat. The researchers demonstrated that with mice: “Bone marrow transplants of stem cells that produce leucocytes lacking IL-6 (the cytokine interleukin 6) or when injected with antibodies that block IL-6 prior to stress exposure, the development of social avoidance … Continue reading If research treats “Preexisting individual differences” as a black box, how can it find causes for stress and depression?

Do our unique visual perceptions arise from brain structural differences?

This 2014 UK/German human study involved fMRI scans of the subjects inferior temporal cortex while viewing images: “Brain representational idiosyncrasies accessible to fMRI are expressed in an individual’s perceptual judgments. We found evidence for an individually unique representation predictive of perceptual idiosyncrasies in hIT [human inferior temporal cortex] (but not in early visual areas) and … Continue reading Do our unique visual perceptions arise from brain structural differences?

The lifelong impact of maternal postpartum behavior

This 2018 French/Italian/Swiss rodent study was an extension of the work done by the group of researchers who performed Prenatal stress produces offspring who as adults have cognitive, emotional, and memory deficiencies and Treating prenatal stress-related disorders with an oxytocin receptor agonist: “Reduction of maternal behavior [nursing behavior, grooming, licking, carrying pups] was predictive of … Continue reading The lifelong impact of maternal postpartum behavior

Sex-specific impacts of childhood trauma

This 2018 Canadian paper reviewed evidence for potential sex-specific differences in the lasting impacts of childhood trauma: “This paper will provide a contextualized summary of neuroendocrine, neuroimaging, and behavioral epigenetic studies on biological sex differences contributing to internalizing psychopathology, specifically posttraumatic stress disorder and depression, among adults with a history of childhood abuse. Given the … Continue reading Sex-specific impacts of childhood trauma

Obtaining convictions with epigenetic statistics?

This 2018 Austrian review subject was forensic applications of epigenetic clock methodologies: “The methylation-sensitive analysis of carefully selected DNA markers (CpG sites) has brought the most promising results by providing prediction accuracies of ±3–4 years, which can be comparable to, or even surpass those from, eyewitness reports. This mini-review puts recent developments in age estimation … Continue reading Obtaining convictions with epigenetic statistics?

DNA methylation and childhood adversity

This 2017 Georgia human review covered: “Recent studies, primarily focused on the findings from human studies, to indicate the role of DNA methylation in the associations between childhood adversity and cardiometabolic disease in adulthood. In particular, we focused on DNA methylation modifications in genes regulating the hypothalamus-pituitary-adrenal axis as well as the immune system.” Recommendations … Continue reading DNA methylation and childhood adversity

Beliefs about genetic and environmental influences in twin studies

This 2017 Penn State simulation found: “By taking advantage of the natural variation in genetic relatedness among identical (monozygotic: MZ) and fraternal (dizygotic: DZ) twins, twin studies are able to estimate genetic and environmental contributions to complex human behaviors. In the standard biometric model when MZ or DZ twin similarity differs from 1.00 or 0.50, … Continue reading Beliefs about genetic and environmental influences in twin studies

How one person’s paradigms regarding stress and epigenetics impedes relevant research

This 2017 review laid out the tired, old, restrictive guidelines by which current US research on the epigenetic effects of stress is funded. The reviewer rehashed paradigms circumscribed by his authoritative position in guiding funding, and called for more government funding to support and extend his reach. The reviewer won’t change his beliefs regarding individual … Continue reading How one person’s paradigms regarding stress and epigenetics impedes relevant research

A limited study of parental transmission of anxiety/stress-reactive traits

This 2016 New York rodent study found: “Parental behavioural traits can be transmitted by non-genetic mechanisms to the offspring. We show that four anxiety/stress-reactive traits are transmitted via independent iterative-somatic and gametic epigenetic mechanisms across multiple generations. As the individual traits/pathways each have their own generation-dependent penetrance and gender specificity, the resulting cumulative phenotype is … Continue reading A limited study of parental transmission of anxiety/stress-reactive traits