Super Touching Serotonin Edition
Fans and athletes alike produce serotonin (5HT) for game day; 80-90% of it is made by our stomach’s enterochromaffin cells (the rest is made in our brains) and then transported and distributed throughout our bodies.
Touch, or “good hands,” is a Super Bowl fundamental, as any big play – made or broken – is sparked by a finger’s give-and-take. Today’s serotonin system focus is on touch, in particular, serotonergic and dopaminergic activity. From the National Institutes of Health (PubMed), our Super Bowl line-up includes three 2015 articles and one from the archives (2005). The serotonin touch-tales include: brain trauma (blast) and the serotonin N-acetyltransferase gene (Aanat), food metabolism (tryptophan) and the kynurenine pathway, ADHD changes with age, and, the one from the archives, touch/massage therapy decreases cortisol and increases dopamine and serotonin.
Have a Serotonergic Super Bowl All!
I. Blast-related Brain Injury and the Serotonin N-Acetyltransferase Gene (Aanat)
“Long-term molecular changes in the brain resulting from blast exposure may be mediated by epigenetic changes like DNA methylation that regulate gene expression. … Functional validation via gene expression analysis of 30 differentially methylated neuronal and glial genes showed a 1.2 fold change in gene expression of the serotonin N-acetyltransferase gene (Aanat) in blast animals (p < .05). These data provide the first genome-based evidence for changes in DNA methylation induced in response to multiple blast overpressure exposures. In particular, increased methylation and decreased gene expression were observed in the Aanat gene, which is involved in converting serotonin to the circadian hormone melatonin and is implicated in sleep disturbance and depression associated with TBI.”
Neuronal DNA Methylation Profiling of Blast-related Traumatic Brain Injury (TBI).
Haghighi F, Ge Y, Chen S, Xin Y, Umali MU, De Gasperi R, Gama Sosa MA, Ahlers ST, Elder GA.
J Neurotrauma. 2015 Jan 16. [Epub ahead of print]
PMID: 25594545 [PubMed - as supplied by publisher]
II. Kynurenine Pathway (Food/Tryptophan Metabolism) and Serotonin Circuits
“The kynurenine pathway of tryptophan metabolism is involved in the pathogenesis of several brain diseases, but its physiological functions remain unclear. We report that kynurenic acid, a metabolite in this pathway, functions as a regulator of food-dependent behavioral plasticity in C. elegans. The experience of fasting in C. elegans alters a variety of behaviors, including feeding rate, when food is encountered post-fast. Levels of neurally produced kynurenic acid are depleted by fasting, leading to activation of NMDA-receptor-expressing interneurons and initiation of a neuropeptide-y-like signaling axis that promotes elevated feeding through enhanced serotonin release when animals re-encounter food. Upon reseeding, kynurenic acid levels are eventually replenished, ending the elevated feeding period. Because tryptophan is an essential amino acid, these findings suggest that a physiological role of kynurenic acid is in directly linking metabolism to activity of NMDA and serotonergic circuits, which regulate a broad range of behaviors and physiologies.”
Kynurenic Acid Is a Nutritional Cue that Enables Behavioral Plasticity.
Lemieux GA, Cunningham KA, Lin L, Mayer F, Werb Z, Ashrafi K.
Cell. 2015 Jan 15;160(1-2):119-31. doi: 10.1016/j.cell.2014.12.028.
PMID: 25594177 [PubMed - in process]
III. Age, ADHD and Dopaminergic and Serotonergic Genes
“Elucidating genetic mechanisms involved in Attention-Deficit/Hyperactivity Disorder (ADHD) has been challenging. Relatively unexplored is the fact that genetic mechanisms can differ with age. The current study explored the association between dopaminergic and serotonergic genes, ADHD symptoms, and neurocognitive functioning in relation to age. … Our results are preliminary, but may point to differential genotype-phenotype associations at different ages. This can be seen as a proof of concept for the importance of age in dopaminergic and serotonergic genetic association analyses. Our findings are consistent with the idea that genetic and neurocognitive mechanisms underlying ADHD may change throughout life.”
The role of age in association analyses of ADHD and related neurocognitive functioning: A proof of concept for dopaminergic and serotonergic genes.
Thissen AJ, Bralten J, Rommelse NN, Arias-Vasquez A, Greven CU, Heslenfeld D, Luman M, Oosterlaan J, Hoekstra PJ, Hartman C, Franke B, Buitelaar JK.
Am J Med Genet B Neuropsychiatr Genet. 2015 Jan 14. doi: 10.1002/ajmg.b.32290. [Epub ahead of print]
PMID: 25586935 [PubMed - as supplied by publisher]
IV. Massage (Touch) Decreases Cortisol and Increases Dopamine and Serotonin
“In this article the positive effects of massage therapy on biochemistry are reviewed including decreased levels of cortisol and increased levels of serotonin and dopamine. The research reviewed includes studies on depression (including sex abuse and eating disorder studies), pain syndrome studies, research on auto-immune conditions (including asthma and chronic fatigue), immune studies (including HIV and breast cancer), and studies on the reduction of stress on the job, the stress of aging, and pregnancy stress. … These studies combined suggest the stress-alleviating effects (decreased cortisol) and the activating effects (increased serotonin and dopamine) of massage therapy on a variety of medical conditions and stressful experiences.”
Cortisol decreases and serotonin and dopamine increase following massage therapy.
Field T, Hernandez-Reif M, Diego M, Schanberg S, Kuhn C.
Int J Neurosci. 2005 Oct;115(10):1397-413.
PMID: 16162447 [PubMed - indexed for MEDLINE]
Video: The most important lesson from 83,000 brain scans, Daniel Amen, TEDxOrangeCoast
*Tomorrow: New Homeostasis with Publius’ Super Bowl of Cannabinoid Science.
Posted by Bryan W. Brickner