In high school we are taught that brain cells do not repair themselves once they are damaged no matter what, but now that I am taking upper level biology courses I have found this is not the case. Recently, I have begun learning that adults can grow new neurons and repair themselves in certain areas of the brain. Regulated by growth factors, neurogenesis develops new brain cells from multi-potent neural stem cells which divide in the brain into neurons or glia. These cells move away from the multi-potent cells to mature and those that survive make connections with neurons and are able to begin sending signals. This process has been shown to occur in both the hippocampus and the olfactory bulb. Neurogenesis offers hope to those suffering from many neurological disorders including Parkinson’s, Alzheimers, and Huntingtons through the use of drugs that stimulate areas of the brain to replace its own cells.
A recent study on adult neurogenesis involved the possibility of preventing cocaine addiction and relapse by increasing neurogenesis in the hippocampus. Researchers used lab rats to test their hypothesis by demonstrating that decreasing neurogenesis by blocking new growth of certain nerve cells increases vulnerability for cocaine addiction and relapse. Those involved aimed to decrease the neurogenesis in the brain and believe it could potentially help those being medically treated with potentially addictive medications, as well as those who are recovering from addiction. The hippocampus is the center of memory and learning, and it makes sense that altering the part of the brain that forms drug-context relationships could help to prevent relapse by helping to forget associations previously made while using the drug. They tested their theory by first manipulating the grow of the neural cells through advanced radiation delivery techniques in order to prevent growth in the hippocampus. Researchers found that rats where more likely to self administer cocaine with a lever than those who did not receive radiation. A second test with the rats involved them first self administering cocaine with the lever, and a round of radiation while not ingesting the drug. Rats that were radiated, with decreased neurogenesis, took longer to realize when there was no longer cocaine attached to the lever. Because the addicted rats continued to push the lever even though there was no physical satisfaction or stimulation of receiving the drug, it supports the notion that decreased neurogenesis fueled the process of addiction rather than the actual drug changing the brain.
Do you think that manipulating a single part of the brain can really have a large impact on improving or curing addiction to drugs? Addiction is more than just a memory formed one region of the brain, the hippocampus. Addiction is physical and takes a toll on your body. Also, many drugs affect pleasure regions in the brain so one would think the neuron growth would need to be reduced in multiple places in order for this to be plausible.
Posted by Asia Barnes (7)