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Symbiotic Biofilms and Brain Neurochemistryкнига
- Автор: Oleskin A.V.
- Год издания: 2010
- Издательство: Nova
- Местоположение издательства: Hauppauge, N.Y., United States
- Объём: 57 страниц
- ISBN: 978-1-61761-005-9
- Аннотация: An overwhelming majority of known species of microorganisms form biofilms, i .e., spatially and metabolically structured communities embedded in the extracellular biopolymer matrix. Biofilm development is a complex multi-stage process involving reversible and, at a later stage, irreversible attachment of microbial cells to the substrate surface, matrix formation, three-dimensional structuring of the whole community including the formation of mushroom- or pillar-shaped structures and, finally, the degradation of the biofilm and the dispersion of the cells involved. These processes are considered in the example of microorganisms that interacts with the animal or human organism, playing the roles of symbionts or pathogens. In particular, the microorganisms of the gastro-intestinal (GI) tract interconvert between two different lifestyles: they can exist as planktonic cells in the intestinal lumen or form part of a biofilm attached to the mucous membrane of the GI tract. The GI microflora, including the biofilm-forming cells, is subject to regulation by the metabolites and chemical signals produced by the human/animal host. The data published in the literature and our own findings suggest an important role of host-produced neuromediators, such as amines, peptides, and nitric oxide, which regulate biofilm formation by influencing microbial growth rate, the aggregation of microbial cells, the formation of microcolonies, and matrix synthesis. Our results were obtained using high efficiency liquid chromatography and revealed that cells of various symbiotic and pathogenic bacterial species contain serotonin, norepinephrine, and dopamine, as well as their precursors and oxidative deamination products. It follows from our studies with Escherichia coli that the culture of this symbiotic, biofilm-forming bacterium releases amine neuromediators and their precursors/products into the culture fluid in concentrations of 10--100 nM, which are sufficiently high to cause the host’s physiological response. These facts and other relevant data are considered in the article in terms (i) of the autoregulatory role of neuromediators in the biofilm-forming microbial population and (ii) the microbially-produced neuromediator amines’ impact on the human organism. Of particular interest in this respect are the data that the culture fluid of E. coli contains over 1 micromole/l DOPA, the catecholamine precursor. DOPA, the catecholamine precursor, crosses the gut-blood and blood-brain barriers. In the brain, DOPA is also converted to dopamine and thereupon to norepinephrine that regulate brain processes involved in locomotion, affection, sociable and dominant behavior, as well as aggression.
- Добавил в систему: Олескин Александр Владимирович