By Edyta Zielinska
Mice raised in isolation from their mothers developed cognitive deficits similar to those of babies raised in orphanages where physical contact is infrequent.
Excerpt: Earlier studies had shown that human children raised in isolation or abusive conditions had less white matter in their prefrontal cortex—the part of the brain involved in memory, decision making, and social interactions.
My comment: Doesn’t lowering stress promote the development of white matter via what would otherwise be a negative effect of cortisol suppression on the development and function of the adaptively evolved mammalian hypothalamic gonadotropin releasing hormone (GnRH) neurogenic niche, which is responsible for nutrient chemical-dependent and pheromone-dependent brain development? That was a rhetorical question.
GnRH modulates luteinizing hormone (LH), and a quick glance through the extant literature on neuroendocrine and neuroimmune system function in mammals would show how both GnRH and LH are clearly involved in development of myelination of white matter and differences in gray matter. Stress, for example, negatively impacts both the neuroendocrine and neuroimmune system, which are modulated by GnRH.
What a quick glance would not show is how the epigenetic effects of nutrient chemicals and pheromones cause adaptive evolution and the development of the mammalian hypothalamic GnRH neurogenic niche. For that, you have to look back at the ecological and social niche construction that precedes neurogenic and cognitive niche construction. Across the continuum of ecological, social, neurogenic, and cognitive niche construction we have the conservation of GnRH and diversification of its receptor.
Kochman 2012 had this to say: “The discovery of the fact that one decapeptide molecule, among the GnRHs, was constructed perfectly at the beginning of 400 million years evolution and that it is not possible to improve its physiological potency using the any natural amino acid is, in my opinion, important, fascinating and beautiful.”
The fascinating role of GnRH is central to my model of how nutrient chemicals and pheromones cause adaptive evolution via their effects on LH. The abysmal lack of knowledge of current molecular biology that links the epigenetic effects of nutrient chemicals and pheromones directly to the secretion of hypothalamic GnRH in humans, and to LH secretion and myelination in mammals via exposure to odors and pheromones that are important to brain development, seems destined to delay the realization that human brain development is as dependent on pheromones as it is on nutrient chemicals.
These results extend the requirement for mammalian pheromone-dependent myelination to human infants raised with minimal social contact. The absence of social odors (the pheromones) shows up in behavior caused by their otherwise “normal” epigenetic effects.