News & Views in 2013

While effectively doubling the number of known odorant-to-receptor pairings in human olfaction, researchers explain a portion of perceptual variability that stems from genetic variability.

A study shows that when mice are taught to fear an odor, both their offspring and the next generation are born fearing it. The gene for an olfactory receptor activated by the odor is specifically demethylated in the germ line and the olfactory circuits for detecting the odor are enhanced.

Long-term exposure to females reduces aggression of male fruit flies. The mechanism involves contact-dependent pheromone sensing and the activation of a small group of GABAergic inhibitory neurons unique to the male brain.

A study finds that immune factors transmitted through breast milk regulate the cognitive function of offspring. Changes in milk composition alter hippocampal development and have effects on memory that last into adulthood.

The cerebellum, with its stereotypic anatomy, has served as an engine of discovery for developmental neurobiologists and cancer biologists alike. However, new findings reported in this issue of Nature Neuroscience suggest that its anatomy and cellular specification, and by extension, its tumor biology, may be less simple than previously believed.

In synaptic integration, timing is everything. A new study demonstrates that voltage-activated ion channels transform spatially distributed synaptic input into a coherent neuronal output by countering time delays in the dendritic tree.

Errors are typically followed by more cautious responses. A study now provides evidence that remarkably conserved neural dynamics underlie these post-error adjustments to behavior in rodents and humans.

A study in this issue of Nature Neuroscience demonstrates that astrocytic transforming growth factor-β facilitates complement-mediated removal of weak synapses by microglia during the synaptic pruning period.

A study now identifies an unexpected function of the D2 dopamine receptor in synapse maturation during a critical period in mice. The findings may have implications for the onset of schizophrenia in humans.

Each olfactory sensory neuron in mice is defined by which of the ∼1,000 odorant receptor genes that it expresses. Using optogenetics, a study finds that mice can perceive stimulation of only a single class of olfactory sensory neuron.

Two studies emphasize similarities in the developmental origin of cortical interneurons across mammals. They suggest that most interneurons in humans and macaques have a subcortical origin.

We know that humans are capable of learning during sleep. Research now shows that they are also capable of unlearning during sleep, and in a way that alters the neural representation of a feared stimulus: re-exposure to an odor during slow-wave sleep promotes extinction of an aversive visual association learned in that odor context.

The ability to categorize objects depending on task demands is critical. A primate study finds that the prefrontal cortex signals to the parietal cortex during categorization, indicating an asymmetric, top-down interaction.

Gupta et al. report in this issue that, in Drosophila melanogaster, a dietary supplement of spermidine—a polyamine originally isolated from semen—protects against cognitive aging by acting through the autophagic pathway.

High-grade glioblastomas survive glucose-poor environments by becoming more stem cell–like. Increased glucose uptake by the transporter Glut3, a new biomarker of poor clinical outcome, drives this enhanced malignant progression.

People are able to form preferences for unfamiliar items, such as new books or foods, before experiencing them. A study in this issue of Nature Neuroscience finds that prospective evaluations of unfamiliar items can be based on stored neural representations of relevant, familiar items.

A study reveals that SIRPα is released from postsynaptic neurons to induce and mature their synaptic inputs, using CD47 as the presynaptic receptor. SIRPα is cleaved in an activity-dependent manner to act as retrograde signal.

TMEM16C has an unexpected role in regulating the activity and cell surface expression of sodium-activated potassium (SLACK) channels. By enhancing SLACK currents, TMEM16C indirectly inhibits pain signaling.

With evidence from model organisms and human population genetic analysis, two studies in this issue report discoveries that eukaryotic Top3β has RNA topoisomerase activity and, in a ribonucleoprotein complex with FMRP, is important for neurodevelopment and normal cognition.