Species specificity in gene expression in the brain
By Edyta Zielinska | August 1, 2012
Excerpt: “Researchers took thin slices from regions of the brain involved in processing visual and sensory information and scanned them for the in situ expression of 1,000 genes that act as markers of cell type or are involved in disease, evolution, or cortical function.”
My comment (in the context of mammals):
Species specific differences in cell type are linked via olfaction and pheromones to differences in tissue type (e.g., cells in tissues). The development of the neuroendocrine and neuroimmune systems is dependent on the central role of gonadotropin releasing hormone (GnRH) nerve cells in brain tissue that regulates the secretion of most, if not all, other hormones that have been indirectly linked from non-olfactory/pheromonal input to brain development and behavior.
The epigenetic effect of nutrient chemicals and pheromones directly links food odors and social odors/pheromones via GnRH to the beneficial effects of homeostasis or detrimental effects of inflammation (as in processes that underlie the development of some cancers). Therefore, the question to be answered is not about the number of genes that act as markers of cell type or are involved in disease, evolution, or cortical function. Indeed, the more important question to first ask is what epigenetic effects of sensory input on receptor-mediated events are directly involved in the development of genetically predisposed diseases.
When researchers examine gene expression in slices from regions of the brain involved in processing sensory information in attempts to locate species specific markers of cell types involved in disease, evolution, or cortical function, shouldn’t they look first at gene expression that is altered by species-specific olfactory/pheromonal input? That might help determine both the differences and the similarities among disease processes common in species from mice to man.
Chemical ecology is, of course, responsible for adaptive evolution via ecological, social, neurogenic, and socio-cognitive niche construction (i.e., brain development). How could anything else but chemicals (nutrient chemicals and pheromones) be responsible for similarities and differences in cell types of the brain in different species?