May 3, 2012 § Leave a comment
Researchers at the Southwestern Medical Center have published results of a study in the Journal of Neuroscience that links the manipulation of gene Nf1 to neurogenetic improvements, which makes the brain more sensitive to the effects of antidepressants.
By performing genetic experiments on mice, the researchers found that deleting gene Nf1 altogether resulted in long-lasting improvements in neurogenesis. It increases the development of neurons in the brain during the aging process, sensitizing the mice to antidepressants.
The researchers deleted the gene that codes for protein Nf1 in mice, leaving other tissues untouched. Those mice in which the protein was deleted showed greater neurogenesis than the control group without the deletion. The team tested for this improvement by performing behavioral tests such as observed behaviors in both anxious and relaxed moods. The test group mice purportedly formed more neurons over time. Also, young mice lacking the protein required far less of a dosage of antidepressants to treat stress. Older mice lacking the protein responded as though they had been taking the antidepressant for their entire lives.
Dr. Luis Parada, director of the Kent Waldrep Center for Basic Research on Nerve Growth and Regeneration and senior author of the study said, “The significant implication of this work is that enhancing neurogenesis sensitizes mice to antidepressants – meaning they needed lower doses of the drugs to affect ‘mood’ – and also appears to have anti-depressive and anti-anxiety effects of its own that continue over time.” He goes on to explain that in mice, just as in humans, the rate of production of new neurons decreases with age and stress. Learning, exercise, electroconvulsive therapy, and some antidepressants can increase neurogenesis.
Parada says, “In neurogenesis, stem cells in the brain’s hippocampus give rise to neuronal precursor cells that eventually become young neurons, which continue on to become full-fledged neurons that integrate into the brain’s synapses.” He summarizes that, “this work suggests that activating neural precursor cells could directly improve depression- and anxiety-like behaviors, and it provides a proof-of-principle regarding the feasibility of regulating behavior via direct manipulation of adult neurogenesis.”
The Nf1 gene has long been known to cause mutations that prompt tumors to grow around nerves. Parada and his colleagues at the Southwestern laboratory have published many studies linking the Nf1 gene to effects in several major tissues. They will continue to study the effects of the absence of this protein.
“Genetic Manipulation Boosts Growth of Brain Cells Linked to Learning, Enhances Effects of Antidepressants”. (March 10, 2012). Neuroscience News. March 11, 2012. http://neurosciencenews.com/genetic-manipulation-grows-brain-cells-learning-antidepressants/.