October 23, 2008
More Methylation In Suicide Brain Genomes
Methyl groups placed on the DNA backbone of our genomes regulate gene expression. People who commit suicide have more methylation on a gene that produces a receptor for a neurotransmitter. Maybe a reduction in the amount of that neurotransmitter receptor causes depression and suicide.
There are an increasing variety of epigenetic mechanisms that have been described, including the regulation of gene function via the methylation or demethylation of DNA. The study by Drs. Michael Poulter and Hymie Anisman and colleagues in the October 15th issue of Biological Psychiatry illustrates one exciting new example in this area of research, an epigenetic study of depression/suicide. The researchers compared the brain tissues of those who had major depressive disorder and committed suicide to those from a control group who died suddenly, from heart attacks and other causes.
They found the genome in people who have committed suicide as a result of major depression was being chemically modified by a process that is normally involved in regulating cell development. As Poulter explains, "We have about 40,000 genes in every cell and the only reason a skin cell becomes a skin cell as opposed to a heart cell is because only a fraction of the genes are being expressed, and the other genes not being expressed are shut down by this genetic process of DNA methylation." The rate of methylation in the suicide brains was found to be nearly ten times that of the control group, and the gene being shut down was a neurotransmitter receptor that plays a major role in regulating behavior. John H. Krystal, M.D., Editor of Biological Psychiatry and affiliated with both Yale University School of Medicine and the VA Connecticut Healthcare System, comments, "This is exciting new evidence that genetic and environmental factors may interact to produce specific and long-lasting modifications in brain circuits. Further, these modifications may shape the course of one's life in extremely important ways, including increasing the risk for major depressive disorder and perhaps suicide."
So if people in the future build a time machine, go back to 1991, and demethylate Kurt Cobain's DNA then suddenly we'll have more Nirvana albums. If you notice a change in the number of Nirvana albums you can attribute the change to time travelers.
That could be a really great biological weapon:
A virus that causes suicide.
Of course, the evil genius of this is too much for mere humans. Evolutionary arms races, on the other hand, have no qualms about epistastatic gene silencing as an extended phenotype.
I await an "appropriate" Finn joke over at gnxp.
Yeah, more Nirvana albums, but those Nirvana Albums will suck.
You ever noticed that good rock singers are not exactly mentally stable. They are prone to depression which usually does not result in suicide but in drinking/drugs/multiple failed relationships. It's not like he would have stayed with Courtney Love, even if he lived.
Usually when people get over these issues (if they do) their music starts to suck, especially after the settle down and get married.
Beattles best stuff if when they were on drugs. Marriage killed the band. Janis, Hendrix, Morrison and a host of others were all addicts. Led Zeplen a bunch of boozers and druggies. List goes on.
I was never into Nirvana, Kurt was a wussy...I was more into Soundgarden and Alice in Chains, that was some angry/brooding depression, much better. :-)
One thing I have noticed is that rappers rarely have these type of issues, but usually there biggest problem is related to violence. There are very very very few rappers who ever end up in rehab or drunks. A lot of rappers end up in trouble for fighting people or getting caught with guns, a handful actually shoot some one or get shot. I wonder why this is? It seems creativity in different types has different "side effects". :-)
Damn...forgot STP (Stone Temple Pilots) favorite Alternative Band of all times...lead singer (Weiland) a major heroin addict, who still can't stay clean for one tour no matter what groups he is with. Damn good music though.
Depression and violence have both been associated with dietary intake of fish. The less fish consumed, higher incidences of murder and depression. If you like angry music check out dystopia's HUMAN=GARBAGE album.
Interesting that depression seems to correlate with excess methylation, even though SAMe (S-adenosyl-l-methionine) which enhances methylation is touted as an antidepressant.
(S-adenosyl-L-methionine as an Antidepressant
Since a disrupted circadian rhythm is associated with both depression and methylation related epigenetic changes, I wonder if there is a connecton. BTW, a disturbed circadian cycle seems to promote cancer as well.
Depression could be a defensive mechanism. Manic episodes can be very creative, which benefit our species, but can be destructive to the individual. Handel`s messiah was written during a manic episode. Depression could be acting like a circuit breaker. A disrupted circadian rhythm makes a lot of sense.