How individuality develops? Experience leads to the growth of new brain cells.” May 9th, 2013.
News article excerpt: “Our findings show that development itself contributes to differences in adult behavior. This is what many have assumed, but now there is direct neurobiological evidence in support of this claim. Our results suggest that experience influences the aging of the human mind.”
My comment: In our 1996 Hormones and Behavior review article “From Fertilization to Adult Sexual Behavior” we included a section on molecular epigenetics. It established the context of how sensory input from the environment influences the development of our brain and behavior. I’ve since developed a model with more details of how nutrition associated with food odors and socialization associated with pheromones are responsible for the adaptive evolution of our brain and behavior.
Article published in Science: Emergence of Individuality in Genetically Identical Mice
Excerpt: Stochastic gene regulation may lead to individual differences in molecular states, which are further amplified through experience. (iii) Animals might show small changes in the epigenetic state of their genome and may drift epigenetically apart over time, which reflects the cumulative effects of the choices they make in the course of their lives.
My comment: My specific focus has been on the molecular mechanisms of nutrient-dependent pheromone-controlled stochastic gene regulation:
“This model of systems biology represents the conservation of bottom-up organization and top-down activation via:
Nutrient stress-induced and social stress-induced intracellular changes in the microRNA (miRNA) / messenger RNA (mRNA) balance;
Intermolecular changes in DNA (genes) and alternative splicing;
Non-random experience-dependent stochastic variations in de novo gene expression and biosynthesis of odor receptors;
The required gene-cell-tissue-organ-organ system pathway that links sensory input directly to gene activation in neurosecretory cells and to miRNA-facilitated learning and memory in the amygdala of the adaptively evolved mammalian brain;
The required reciprocity that links gene expression to behavior that alters gene expression (i.e., reciprocity from genes to behavior and back) in model organisms like the honeybee.”
Thus, my model addresses the missing molecular mechanisms in the context of the Science article’s concluding sentence: “The present paradigm serves as an animal model for addressing the “mystery and controversy” (2) of the nonshared environment, or the ways in which living our lives makes us who we are (29).”
In Human pheromones and food odors: epigenetic influences on the socioaffective nature of evolved behaviors it is clearer how epigenetic cause and effect eliminate “…the “mystery and controversy” (2) of the nonshared environment…” My model explains how nutrition and socialization during our lives makes us who we are (e.g., in the context of adaptive evolution).
James V. Kohl detailedl how quantized energy-dependent microRNA biogenesis links the pheromone-controlled physiology of reproduction to biophysically constrained viral latency and healthy longevity. Links from what organisms eat to the enzyme-dependent metabolism of food also link metabolic networks to microRNA-mediated genetic networks in the context of RNA interference. Drug therapies alter RNA interference by altering cell type differentiation in all cells of all individuals of all species. For comparison, during the past 26 years, Kohl has detailed how the chemistry of protein folding is biophysically constrained at every level of biological organization by conserved molecular mechanisms.