Studies in recent years have shown that some brain regions continue to generate new neurons even during adulthood. The significance of these newborn cells for brain function remains unclear, as does the potential benefit of increasing their numbers. A new study in the June issue of Nature Neuroscience fails to find a causal relationship between behavioral improvements and increased neurogenesis in adult mice.
Laboratory mice housed in cages with extra room, toys and social interaction are less anxious and learn better than mice housed in typical cages, and they also generate more new neurons in the hippocampus, a brain area important for learning and memory. René Hen and colleagues blocked neurogenesis in the hippocampus of adult mice with x-ray radiation before housing them in enriched environments. After six weeks, irradiated mice showed the same improvement in learning and decrease in anxiety-like behavior as non-irradiated mice, suggesting that these behavioral effects were not due to an increase in new hippocampal neurons.
René Hen (Columbia University, New York, NY, USA)
Abstract available online.
(C) Nature Neuroscience press release.
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