A new study out of the University of California, San Diego School of Medicine suggests that learning new actions causes structural changes in the brain. This new research improves the basic understanding of how the brain learns.
According to one of the study’s authors, Mark H. Tuszynski, MD, PhD and director of the Center for Neural Repair at the UC San Diego, as well as a neurologist at the Veterans Affairs San Diego Health System, the general belief was that a whole brain or cortical region would change when learning occurred and that a large group of neurons (brain cells) would show a modest change in overall structure. The new findings, however, show that this is not the case. Instead what is believed to occur is that a small number of specific cells activated by learning show an expansion in structure. This highlights how structurally flexible the brain is in context with normal learning and emphasizes how adaptable it is as part of its normal physiology.
The study was performed by examining the spinal motor nerves of rats after being taught how to grasp with their forelimb. The neuron cells collected were separated based on their projection patterns and their contribution to the grasping motor function. The results were noticeable structural adaptations in both the density and complexity, and were restricted only to these motor neurons. The neurons associated with the surrounding musculature where unaffected.
More research is needed to see if these new connections and changes are permanent. In rats, reaching and grasping food is a learned behavior requiring time and practice to master. This behavior is similar to when a person learns a new action like riding a bike or playing a musical instrument. As in any area of memory encoding, if the behavior is not continued regularly, preferably daily for several consecutive days, it can be forgotten or the motions become hard to remember.
Works Cited
Wang, L., Conner, J., Rickert, J., & Tuszynski, M. (2011, January 21). Structural plasticity within highly specific neuronal populations identifies a unique parcellation of motor learning in the adult brain. Proceedings of the National Academy of Sciences , published ahead of print .
