News & Views in 2014

The retina encodes visual information and sends it to the brain. We now learn that this neural code varies strongly with light adaptation. Does this mean a change in the message or a change in the way that the message is coded?

Loss of the receptor tyrosine kinase ErbB4 in somatostatin (SOM) inhibitory neurons of the thalamic reticular nucleus (TRN) enhances top-down cortical feedback, improving feature detection at the cost of reduced ability to switch attention. The study furthers our understanding of the circuit mechanisms underlying TRN function.

Single-unit recording in primate cortical area MT shows surprising sensitivity to depth defined by dynamical perspective cues. Depth might then be computed through recurrent circuits involving signals downstream of MT.

A study finds that formation of a cognitive map for a virtual reality environment demands associating specific movement trajectories with views to the constellation of peripheral landmarks.

A study links transient activation of the brain's reward system during a novel experience to frequent reactivation of memory traces during sleep and shows that artificial activation of the reward circuit can strengthen memories.

A study demonstrates that learning different character sets produces a repeatable arrangement of distinct cortical modules, suggesting that a preexisting cortical architecture is repurposed during learning.

A study now provides proof of concept that restoration of Ras-Erk signaling during adulthood rescues cellular and cognitive phenotypes in mouse models of the genetic disorder Noonan syndrome.

A randomized clinical trial in older adults shows that high dietary intake of cocoa flavanols enhances memory performance on an object-recognition task and neural activity as assessed by functional magnetic resonance imaging in the dentate gyrus of the hippocampus, a region that is critical for learning and memory.

Patch-clamp recordings and imaging in retina show that electrical synapses between dendrites of neighboring ganglion cells transform spatial patterns of light activated synaptic input into a temporal population code.

Fruit flies seek water, but only when they are thirsty. And imbibing is rewarding only to water-deprived individuals. The effects of thirst on water seeking and on formation of associative memories of drinking water each are mediated by distinct sets of dopamine neurons that innervate restricted zones of the mushroom bodies in the fly brain.

Cortical neurons reduce spiking responses to repetitive sensory stimulation, but the perceptual impact of this adaptation has been difficult to assess. Work now shows that it has profound consequences for tactile perception.

A study finds evidence supporting co-release of glutamate and GABA, excitatory and inhibitory fast neurotransmitters, from a single axon terminal in neurons of the ventral tegmental area that project to the lateral habenula.

Jeremy Bentham distilled animal behavior as avoiding pain and seeking pleasure. Now, using a combination of different methodological approaches, Roy et al. identify a neural mechanism relevant for learning to avoid pain.

Retrosplenial cortex neurons provide a signal akin to a compass readout. Evidence in humans now demonstrates that these neurons anchor their representations locally, locking to the geometry of a room rather than to the city beyond.

The tactile sensors in our fingers have variable sensitivity across the skin. Does this variability harm or help the CNS in touch perception? Work now shows that this variability may provide the CNS with more information about micropositioning and stimulus orientation.

As we learn through visual experience, where does that memory form? A study now shows that neural responses at even the earliest stage of visual cortex get reshaped in a way that faithfully reflects ongoing learning.

How do enhancers facilitate transcription of plasticity-related genes in response to synaptic stimulation? A study implicates a specific histone modification and suggests that FOS regulates enhancer function.

Long axonal projections seem to be metabolically coupled to ensheathing glial cells. Targeting LKB1, a regulator of energy homeostasis, specifically in Schwann cells causes a loss of predominantly small unmyelinated fibers.

Olfaction has often been described as a 'synthetic' sense. A study now reveals a surprising capacity to resolve individual odorants in complex mixtures, with implications for how the nervous system recognizes objects.