The brain contains lymphatic vessels similar to those found elsewhere in the body, a mouse study shows.
June 1, 2015|
“If you go into the literature, 20 years ago, the idea was that if you see immune cells in the brain, something must be going wrong…”
In our 1996 Hormones and Behavior review article, we wrote (with my emphasis):
The immune system has long been known to perceive certain sexual differences, e.g., the presence or absence of H-Y antigen (Simpson, 1991). Mice have been shown to enact kin selection on the basis of major histocompatibility complex characteristics within the perceiving mice and from other mice as chemosensitive identified. Humans have been shown to possess similar immune- related chemosensitive skills (Gilbert, Yamazaki, Beauchamp, and Thomas, 1996; Wedekind, Seebeck, Bettens, and Paepke, 1995).
Gilbert’s group found that humans could detect differences in individual chromosomes from otherwise syngeneic mice, including on the basis (i) of differing X or Y chromosomes or (ii) of differences introduced as nonidentical MHC haplotype (Gilbert et al., 1996). Wedekind et al. (1985) found that human females who were not taking oral contraceptives would select male-scented T-shirts in direct relationship to the males’ MHC-haplotypic difference from each perceiving female’s own MHC-haplotype. This indicates a dual awareness by the perceiver, i.e., of her own haplotype and of haplotypes sensed as different from her own. These findings establish that immunological components have the capacity, at a subconscious level, to contribute to adult human sexual interactions.
In 1985, science fiction author, Greg Bear began to link these RNA-mediated events to virus-driven cell type differentiation and continued to do so in three novels.
1) Blood Music
2) Darwin’s Radio
3) Darwin’s Children
Everything currently known about physics, chemistry, and the conserved molecular mechanisms of RNA-mediated cell type differentiation in all genera links viral microRNAs to entropic elasticity and the anti-entropic epigenetic effects of nutrient-dependent microRNAs to cell type differentiation in all cells of all individuals. This includes cell type differentiation in brain cells via links between the immune system and the RNA-mediated biophysically constrained chemistry of nutrient-dependent protein folding.
Given what is currently known about links from atoms to ecosystems, how could the immune system link to cell type differentiation in the human brain be any less important than the immune system link to cell type differentiation in all cells of all individuals of all genera. Greg Bear once wrote:
…a species-crossing retrovirus that had become one of the major health scourges on the planet. I couldn’t understand the lack of papers and other source material on HERV. Why weren’t they being investigated by every living biologist?
See also: Researchers Find Missing Link Between the Brain and Immune System
He noted that the vessels look different with age, so the role they play in aging is another avenue to explore. And there’s an enormous array of other neurological diseases, from autism to multiple sclerosis, that must be reconsidered in light of the presence of something science insisted did not exist.
My comment: Some scientists still may think that ecological variation linked from viruses to nutrient-dependent ecological adaptations is something that doesn’t exist. If there are any serious scientists among the scientists who are obviously biologically uninformed, they probably should not continue to claim that mutations can somehow be linked from perturbed protein folding to increasing organismal complexity and brain development during life history transitions. Instead, they might want to look for the viruses that cause the changes in the brain and behavior during life history transitions that are linked by a single amino acid substitution. See, for example: Oppositional COMT Val158Met effects on resting state functional connectivity in adolescents and adults
See for comparison: From gene to phene: Scientists demonstrate genetic control of phenotypic variability
…the papers demonstrate a rare example of linkage between genetic variation for a complex behavioral trait and a neural center of behavioral control.
…Ayroles concludes that in systems from engineering to ecosystems, maintaining parameters within a certain range is very critical – and for that reason most systems must have some buffering mechanisms to control variance as an optimal mean.
My comment: The link from genetic variation to a complex behavioral trait is nutrient-dependent and pheromone-controlled in species from microbes to man. That explains why it is rarely exemplified outside that context. Anyone who attributes behavior to genetic variation is ignoring what is currently known by serious scientists about the biological basis of cause and effect in all genera.
Simply put, cause and effect are nutrient-dependent, RNA-mediated, and controlled by the physiology of reproduction. Metabolic networks and genetic networks do not automagically link themselves to RNA-mediated cell type differentiation in the context of ecological variation that must be linked to nutrient-dependent ecological adaptation, or from viruses to genomic entropy.