Drug Abuse and Addiction in Offspring may be Hereditary and have a Connection to Genetics
By Andrew Jin
Definitions:
Nucleus accumbens- A brain structure related to addiction and reward seeking behavior.
Dopamine- It is classified as a catecholamine (a class of molecules that serve as neurotransmitters and hormones).
Morphine- A narcotic pain reliever extracted from opium.
Summary:
A study at the Tufts University Cummings School of Veterinary Medicine in North Grafton, Massachusetts found that moms who are drug addicts before pregnancy can increase the likelihood of drug abuse or other psychiatric disorders in their children and grandchildren. The research showed that drug addiction could be hereditary and have a connection to genetics. Researchers conducted an experiment using rats in which there was an exposure of morphine for 10 days to female, adolescent rats. The rats were then taken off the drugs, and were mated with healthy males three weeks later. Strikingly, it was discovered that the offspring from the mating were less sensitive to the chemical messenger dopamine in the nucleus accumbens. This same change was seen in the grandchildren of the original rats. Since previous studies show that the brain’s dopamine system has been linked to substance abuse, the change in the dopamine system in the nucleus accumbens may cause a higher probability of drug addiction in the offspring. The research is now trying to determine how the expression of genes is altered to produce this effect in the children and grandchildren of the rats exposed to morphine.
Discussion:
I chose this article because it is directly related to the topic we are learning right now in class. Just a few days ago, we had our gene pool baby project where we learned about the passing down of traits and the functions of genes and chromosomes. I remember very clearly the “Do Now: How are traits passed from parents to offspring? Make of list of your traits and identify who gave them to you.” Then, we had a long class discussion regarding which traits are hereditary and which traits are not. I thought it was quite interesting that there was a question of whether drug and alcohol addiction was passed on from mother to child. In fact, if I remember correctly, Mr. Contini said that drug abuse is passed down behaviorally, not genetically. I find it extremely surprising that almost the same day, on November 14th, a study with new and different insights is published. Also, I chose this article because drug abuse is a large problem in our society, with 17% of all women being smokers. There are currently warning labels on cigarettes regarding smoking during pregnancy. However, after further research, should there be new labels saying that smoking and drugs will increase likelihood of drug addiction in the child, even if usage is stopped before pregnancy?
Questions:
1. In the study, the drugs were taken off the morphine for three weeks before mating. If the drug-free period were lengthened to let’s say 8 weeks, would there still be the same change in the dopamine system of the offspring?
2. What causes this change? How is the gene altered?
Citations:
Siegfried, Tom. "Mom's past drug abuse may alter brain chemistry of offspring."
ScienceNews 14 Nov. 2010: n. pag. Web. 19 Nov. 2010.
<http://www.sciencenews.org/view/generic/id/65517/title/
Moms_past_drug_abuse_may_alter_brain_chemistry_of_offspring>.
Link to Article: http://www.sciencenews.org/view/generic/id/65517/title/Moms_past_drug_abuse_may_alter_brain_chemistry_of_offspring
Great Job Andrew. I really liked your discussion and how you directly linked classwork to the CSB. It really is a coincidence that we covered the same information on the day that the study came out. I was surprised to read that the rats lost sensitivity of the dopamine. Overall, good job.
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