Evidence suggests that covert visual attention can improve behavioral performance by modulating contrast or response gain. Here the authors find that the size of the stimulus and the attention field determine which mechanism is used. These results support predictions of the normalization model of attention. Cover image courtesy of Marisa Carrasco.p 1554

Life experiences affect behavior, in part by altering DNA via epigenetic modifications. We present a special focus on the growing field of neural epigenetics with articles highlighting the latest advances in our understanding of these epigenetic mechanisms, their regulation and their role in the nervous system. The cover image is a painting by J. David Sweatt which portrays an abstract representation of the dynamic regulation of epigenetic mechanisms and the resulting downstream effects.12991319

Neurons of the same molecular type can have substantially different intrinsic properties. Padmanabhan and Urban report that intrinsic diversity in the mitral cells of the mouse olfactory bulb decreases the firing correlations between neurons and increases the amount of information that can be transmitted by the neuronal population. The cover image is a painting of idealized mitral cells in the main olfactory bulb by Krishnan Padmanabhan.11581276

The kinase mTOR enhances cell growth in many systems. A new study reports that injury reduces mTOR activity in neurons of the corticospinal tract (CST). Enhancing mTOR activity by inactivating its negative regulator PTEN increases sprouting and regenerative growth of injured CST neurons. The cover shows a sagittal section from the spinal cord of a mouse lacking PTEN in CST neurons 2 months following spinal injury. Sensorimotor cortical axons are labeled in red and astrocytes in blue.1075

(p 944)

Nature Neuroscience presents a special focus issue on neurodegeneration consisting of Reviews and Perspectives that highlight the latest advances in our understanding of pathological mechanisms and the possibility of harnessing this information for translational research. The cover image depicts cells from a mouse model of Huntington's disease with accumulation of lipid droplets (green) as a consequence of inefficient autophagy. The cell bodies are stained red and the nuclei are blue.787–818

Coordinated beating of cilia on the surface of the ependymal cells lining the cerebral ventricles helps circulate cerebrospinal fluid. Tissir et al. demonstrate that regulation of planar cell polarity signaling by the atypical cadherins Celsr2 and 3 is required for the proper development and function of ependymal cilia. The cover shows a scanning electron microscopy image of mouse ependymal cells lining the roof of lateral ventricles, taken from Celsr2 and Celsr3 double knockout mice.654700

(pp 529 and 635)

Chou and colleagues present a comprehensive genetic, anatomical and electrophysiological analysis of local interneurons in the Drosophila antennal lobe, and report an unexpected degree of interneuron complexity and individual variation. (p 439)

Prior work has suggested that neurons in the primary auditory cortex are arranged topographically so that those with similar responses to pure tones are located near each other. Using two-photon calcium imaging, two independent groups now report that tonotopy is only present on a coarse scale, whereas local populations are much more heterogeneous.271353361

Histone deacetylase 1 (HDAC1) is a nuclear enzyme involved in transcriptional repression. Here the authors report that HDAC1 mediates axonal damage by inhibiting mitochondrial transport. On the cover is a pseudo-colored composite micrograph of a mouse cerebellar slice culture stained for HDAC1 and for neurofilament medium and light chains.143180

Nguyen et al. introduce a new biosensor for monitoring neurotransmitter activation. They engineered cells to express both a metabotropic receptor that triggers the Gq protein–coupled receptor cascade to increase calcium concentration and a genetically encoded fluorescent calcium sensor for visualization, thus creating a cell-based neurotransmitter fluorescent engineered reporter (CNiFER). CNiFERs expressing M1 receptors (green) and control cells (blue) in a nest of vasculature (red).p 127