Epigentics and the baby connectome
February 8, 2012 | James Kohl
Excerpt: The proposed framework can be applied to babies of different ages, including premature newborns, and thereby provides a novel tool for unbiased study of structural maturation of the brain. Previously, developmental trajectories could only be studied by measuring anatomy and analyzing separate DTI tracks using tract- or region-of-interest based analysis. We also expect that, by studying brain network topology in newborns, it will become possible to better understand the process of relocation of specific brain functions as a consequence of brain plasticity. The proposed anatomically unconstrained approach to parcellation followed by network-driven analysis of the connectome should facilitate this task.
Recently Hagmann et al.  applied the principles of MR connectomics to explore the contribution of white matter maturation to the development of connectivity between 2 and 18 years. Among other network refinements, they observed a significant increase in node strength and efficiency along with a decrease in clustering.
The contribution of white matter maturation to the development of connectivity between 2 and 18 years can be addressed in the context of food odors and social odors. Brain development is obviously dependent on food odors associated with nutrition. See: Scientists delve into the brain roots of hunger and eating.
In my model the contribution of social odors to brain development is equally important as indicated by the effect of pheromones on luteinizing hormone, steroidogenesis and white matter development.
Zhang et al 2011, for example, bring to bear the fact that new genes for primate intelligence are scattered across the whole genome, demonstrating that they are generated by many independent events including de novo origination, which creates a protein without a parental locus. Since there is no direct effect of non-olfactory/pheromonal sensory input of the environment that would explain gene activation and the intracellular interactions in neurons that might result in de novo gene expression, the most likely driving force for increased primate intelligence appears to be odors associated with nutrition and pheromones associated with socialization.
In mammals, olfactory/pheromonal cause is directly linked to effects on luteinizing hormone and steroidogenesis which also links social odors to sexual differentiation of the brain and behavior.