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Dr. Bob is Robert Hsiung, MD,
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Posted by SLS on September 27, 2014, at 12:37:44
This is no great surprise, but it is important that the effects of negative childhood experiences on the brain can be quantified.
"...children who had experienced abuse in childhood, the degree of that abuse was correlated with methylation of the serotonin transporter and was inversely related to the volume of the hippocampus"
- Scott
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Childhood adversity, epigenetics, and hippocampal volume
At the 2014 meeting of the International College of Neuropsychopharmacology, researcher Booij reported that in humans, there is an interaction between adversity experienced during childhood, and an epigenetic variation in the short form of the serotonin transporter (5HT-T ss, or SLC6A4), which can influence hippocampal volume during depression.
Epigenetics refers to environmental influences on the way genes are transcribed. The impact of life experiences such as stress is not registered in DNA sequences, but can influence the structure of DNA or tightness of its packaging. Early life experiences, particularly psychosocial stress, can lead to the accumulation of methyl groups on DNA (a process called methylation), which generally constricts DNAs ability to start transcription (turning on) of genes and the synthesis of the proteins the genes encode. DNA is tightly wound around proteins called histones, which can also be methylated or acetylated based on events in the environment. When histones are acetylated, meaning that acetyl groups are attached to them, DNA is wound around them more loosely, facilitating gene transcription (i.e. the reading out of the DNA code into messenger RNA, which then arranges amino acids in order to construct proteins). Conversely, histone methylation usually tightens the winding of DNA and represses transcription.
Booij followed 33 children who had experienced some form of adversity at a young age until they were 15 or 16, examining methylation of the serotonin transporter in their T cells and monocytes compared to 36 children who had not experienced adversity during childhood. He found that in children who had experienced abuse in childhood, the degree of that abuse was correlated with methylation of the serotonin transporter and was inversely related to the volume of the hippocampus, as measured using magnetic resonance imaging (MRI). Thus, child abuse yields lasting epigenetic effects (methylation of the serotonin transporter) and has anatomical consequences in teenagers, as seen in smaller hippocampi. These data parallel converse findings by Joan Luby et al. published in the journal PNAS in 2012, in which increased maternal warmth directed toward a child aged 4-7 was associated with increased volume of the hippocampus several years later.
Posted by Phil on September 28, 2014, at 12:15:44
In reply to Childhood adversity, serotonin, and hippocampus, posted by SLS on September 27, 2014, at 12:37:44
I lived it. Still do.
Posted by linkadge on September 28, 2014, at 14:25:39
In reply to Re: Childhood adversity, serotonin, and hippocampus » SLS, posted by Phil on September 28, 2014, at 12:15:44
Yeah, really?
I don't think that SLS was trying to pass of this as his own work. Probably just an oversight in not posting the link.
Linkadge
Posted by linkadge on September 28, 2014, at 20:13:27
In reply to Re: Childhood adversity, serotonin, and hippocampus, posted by linkadge on September 28, 2014, at 14:25:39
I wonder whether the hypermethylation increases or decreases the overall functioning of the transporter?
I know certain antidperessants (esp citalopram and amitriptyline) have antimethylation effects.
Linkadge
Posted by SLS on September 28, 2014, at 22:34:58
In reply to Re: Methylation increase or decrease transporter, posted by linkadge on September 28, 2014, at 20:13:27
> I wonder whether the hypermethylation increases or decreases the overall functioning of the transporter?
As I understand it, it is the methylaytion of the DNA at the promoter site of the serotonin transporter gene that determines the rate of gene expression.
Hypermethylation of the serotonin transporter gene (SLC6A4) = reduced transporter synthesis.
> I know certain antidperessants (esp citalopram and amitriptyline) have antimethylation effects.
Interesting. I guess I should look into that. Thanks.
- Scott
Posted by Lamdage22 on October 15, 2014, at 10:19:49
In reply to Re: Methylation increase or decrease transporter » linkadge, posted by SLS on September 28, 2014, at 22:34:58
So childhood has an effect on later brain chemistry. I am not a scientist, but i have always suspected it.
This is the end of the thread.
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