The effects of perinatal testosterone exposure on the DNA methylome of the mouse brain are late-emerging
Excerpt: “…the emergence of sex differences in the brain may be a gradual process that is cemented over the organism’s life. Our data provide a new perspective by showing that most sex differences in CpG methylation are dynamic and not the result of acute modifications in response to hormones.”
My comment: My model extends epigenetic cause and effect across species of invertebrates and vertebrates to mammals.
“The mammalian model (Diamond et al., 1996) detailed here allows what we have learned from the study of invertebrates (Elekonich & Roberts, 2005; Elekonich & Robinson, 2000) to be used in attempts to understand the development of human behavior and in attempts to understand human physical disease. Those who adopted the position that mammalian pheromones do not exist, or who continue to insist that human pheromones do not exist, have for more than two decades made it seem that there was something ‘fishy’ or ‘funny’ about this model.”
“An environmental drive appears to have evolved from that of food ingestion in unicellular organisms to that of socialization in insects. In mammals, food odors and pheromones cause changes in hormones such as luteinizing hormone (LH), which has developmental affects on sexual behavior in nutrient-dependent, reproductively fit individuals across species of vertebrates (see for review and citations Kohl, 2012). These developmental affects cause the ‘biological embedding’ of responses to the signals that are most important to the survival of individuals and species (i.e. the signals from nutrients that metabolize to species-specific pheromones).”
The link from epigenetic effects of food odors and pheromones via GnRH, LH, and testosterone to affects of differences in hormone secretion on behavior has been clear since 1996. The late emerging effects have also been detailed in the context of how genetic predispositions and experience-dependent epigenetic effects on the differentiation of cell types are linked to sexual orientation.
Nutrient-dependent synthesis of serotonin, oxytocin, and vasopressin alters levels of three brain hormones that affect social behavior. For example, see: Vitamin D hormone regulates serotonin synthesis. Part 1: relevance for autism
What if late emerging epigenetic effects of the metabolism of nutrients to species-specific pheromones links nutrient stress and social stress to brain development via epigenetic effects on amino acid substitutions and on myelination during the cell type differentiation associated with genetically predisposed sexual preferences via hormone-organization and hormone-activation. Could experiences that vary across a lifetime of life history transitions be linked to the development of sexual preferences via conserved molecular mechanisms in species from microbes to man? Or would our 1996 model only apply in some species from insects to elephants?
Is Panksepp correct: “My feeling is that the social brain has many levels. If you don’t understand the foundational level, then you can do brain imaging until you’re blue in the face, but you still will not understand the process at a deep causal level.”