Brain's Balancing Act

A recently published study (gated) performed by scientists at New York University (NYU) Langone Medical Center has found that the ability for humans to learn and adapt to changes in our everyday lives lies in the tiny, miniscule junctions where nerve cells in the brain communicate, neural synapses. Using a powerful imaging technique called two-photon microscopy on the brains of mice, scientists found alterations in the dendritic spines over a period of months. When a mouse learned a new task or was exposed to a new stimulus, scientists observed new spines emerging. Furthermore, as the mice became more improved at specific skills, only a fraction of the new spines would persist. While these spines persisted, scientists noticed that a corresponfing number of older spines that had been formed during the mice's development before the experiment had disappeared. The end result was that only a minute fraction of the mice's spines were gained or lost after exposure to a new experience, while the majority of their existing spines maintained. This study offers insight to how humans, who have at least ten times the amount of dendritic spines on each neuron, are allowed to experience and learn new things everyday without losing existing memories.