Newly generated (red) and mature (green) granule cells in the dentate gyrus region of a mouse brain.NATHAN DANIELSON/COLUMBIA UNIVERSITY'S ZUCKERMAN INSTITUTEAlthough most neurons are generated during development, some brain regions, such as the dentate gyrus region of the hippocampus, continue replacing neurons into adulthood. The function of new cells in this region has so far been unclear, primarily due to their inaccessibility in living animals. Now, using a combination of imaging techniques to observe neural activity in awake mice, researchers at Columbia University have elucidated a role for these new brain cells in learning and memory. The findings were published last week (March 10) in Neuron.
“Other studies had been unable to image the dentate gyrus, let alone the individual cells that reside within it, at this level of detail,” study coauthor Mazen Kheirbek of Columbia said in a statement. “Here, we were able to demonstrate that adult-born granule cells act differently than their mature neighbors, and determine why that difference is so critical.”
Using calcium imaging and a miniature microscope implanted into the brains of live mice, the researchers found that new neurons exhibited a burst of excitability after genesis. To probe the role of this heightened activity in memory, the team exposed the animals to various cue pairings. A particular scent might be paired with a flashing light, for example, while a tone might signify an electric shock. As ...
