Nature Neuroscience

Transplanting new neurons to replace those that are damaged is an important potential treatment for many neurodegenerative diseases, but progress toward such neural replacement therapy has been slowed by the poor integration of these transplants in the host. One culprit is glial cells, reports a new study in the August issue of Nature Neuroscience. These cells, which normally create a barrier (or 'glial scar') between healthy and damaged nerve tissue in response to injury, also make it difficult for newly transplanted neurons to integrate themselves into their new environment.

The authors transplanted retinal cells into adult mice lacking the genes that encode two proteins important for glial scar formation. Several weeks later, the authors found that the transplanted cells had moved into the surrounding host retina and formed what looked like normal retinal neurons. Furthermore, the newly integrated cells were still around as long as six months after transplantation. In contrast, neurons transplanted into normal mice were mostly found clustered near the injection site. These findings suggest that manipulating the scar-forming response of glial cells may increase the chances for successful transplantation therapy.

Nature Neuroscience

Sensory experience can dramatically alter the structure and function of the developing brain. For instance, if one eye is deprived of vision for days to weeks in a young animal (including strabismus in children), then many neurons in the cortex become responsive to the open eye, rather than remaining equally responsive to inputs from both eyes. The molecular events that underlie this reorganization are explored in a new paper in the August issue of Nature Neuroscience.

Long-term depression (LTD) is a well studied form of synaptic plasticity, but its relationship to changes in the brain induced by sensory experience has remained controversial. The new paper now shows conclusively that the effects of monocular deprivation occur by the same pathway as long-term depression. Mark Bear and colleagues show that brief closure of one eye induces the characteristic molecular signature of long-term depression, and that LTD and eye closure cause many of the same functional changes in the visual cortex. Furthermore, monocular deprivation prevents subsequent induction of LTD. As Kimberly McAllister and Martin Usrey discuss in an accompanying News and Views article, this provides the first proof that LTD can be used as model to understand the cascade of cellular changes in the brain that are caused by sensory deprivation.

Nature Neuroscience

Music is a universal feature across all human societies, both ancient and modern. Although the adaptive function of music remains largely mysterious and much debated, research on how the brain processes music has started to influence more general questions in neuroscience. Six reviews in the July issue of Nature Neuroscience highlight this emerging research. The reviews discuss the evolution of music and its development in prelinguistic infants, the complex relationship between language and music processing, the tight coupling between sensory perception and action in music, and what can be learned from studying people with music-related deficits. One review discusses how perfect pitch (the unusual ability to identify the pitch of a sound without any reference point) offers an especially tractable opportunity to examine how specialized cognitive abilities are linked to brain function. The special section is now freely available on Nature Neuroscience's website at http://www.nature.com/
/neuro/journal/v6/n7/index.html.