Articles

In this study, the authors report that target-derived NGF signaling induces the expression of Coronin-1, which consequently gets recruited to the NGF-TrkA–carrying signaling endosome, where it regulates endosomal fusion with lysosomes, trafficking and recycling. In addition, Coronin-1 appears to be necessary for NGF-dependent signaling events such as CREB phosphorylation, Ca²⁺ release and activation of calcineurin.

This study examines neuronal activity coupling between the medial prefrontal cortex (mPFC), basolateral amygdala (BLA) and hippocampus during the recall phase of a differential fear conditioning task and during exposure to a novel open field. The authors show that theta frequency power and synchrony between the mPFC and BLA increase with successful discrimination of aversive versus safe cues, and that the mPFC activity leads that in the BLA during safety.

This study shows that aggressive behavior by male Drosophila melanogaster to another male is attenuated when the aggressor male fly had prior exposure to females. The study also shows that this prior experience-dependent modulation of aggression behavior is mediated by a sexually dimorphic neural circuit and pheromone-based contact chemosensation mechanism.

Attention alters neural responses that encode different aspects of visual stimuli, but exactly how these changes together modulate the encoded spatial representation of a scene remains unclear. Here the authors look at spatial priority maps of attended to and ignored stimuli and find that attention increases the gain but not the size of stimulus representations.

Neurons in the lateral amygdala (LA) with high expression of the transcription factor CREB at the time of fear learning are known to be preferentially recruited to the activated neuronal network for memory recall. The current study shows that artificial activation of high CREB expressing–neurons in the LA using the vanilloid receptor TRPV1 and capsaicin system is sufficient to induce memory recall and promote memory consolidation without external cue and reminders.

The authors find that ACR-23, a ligand-gated cation channel of the cys-loop family, is a betaine receptor and is expressed in worm mechanosensory neurons involved in stimulating locomotion. Excessive activation of ACR-23 leads to paralysis and is responsible for the nematocidal properties of betaine. The authors also find that the action of betaine on ACR-23 is allosterically potentiated by the aminoacetonitrile derivative monepantel, a new antihelminthic drug.

Pyramidal cells have to integrate thousands of inputs across their expansive dendritic arbors. The spatial spread of these inputs should lead to intraneuronal propagation delays. Here the authors show that the distribution of HCN channels in hippocampal pyramidal cells normalizes these delays, particularly for inputs at theta and gamma frequencies.

Saha and colleagues measured the spatiotemporal dynamics of odor representations across populations of neurons in the locust olfactory system during the presentation of two overlapping odors. They report that the performance of locusts in a background-independent odor recognition task is correlated with the ability to decode foreground odor identity from the population activity, suggesting the existence of a background-invariant population code for odorants in this system.

This study shows that spontaneous opening of presynaptic voltage-gated calcium channels (VGCCs) is a major trigger of action potential independent synaptic vesicle release, and finds that R-type channels contribute disproportionately, consistent with a relatively negative activation threshold. The authors also use Ca²⁺ chelation experiments and computational modeling to reconcile how transient Ca²⁺ nanodomains evoked by VGCC opening trigger both spontaneous and action potential evoked neurotransmission.

The primary visual cortex (V1) carries signals related to visual speed, and its responses are also affected by run speed. Here the authors report that nearly half of the V1 neurons were reliably driven by combinations of visual speed and run speed. As a population, V1 neurons predicted a linear combination of visual and run speed better than visual or run speeds alone.

Electrical coupling in the brain usually occurs between inhibitory neurons that are anatomically and functionally similar. Here the authors show that the excitability of inhibitory interneurons in the dorsal cochlear nucleus is controlled by electrical synapses with excitatory projection cells.

The neurodegeneration found in human ataxia-telangiectasia (A-T) is caused by mutations in the ATM (A-T mutated) gene. Li et al. have identified the polycomb group protein with histone methyltransferase activity called EZH2 as a target of the ATM kinase. The study shows that ATM deficiency increases EZH2 stability, thus increasing methylated histone marks. This results in epigenetic changes in transcription that compromise the health and survival of CNS neurons.

The authors find that GABA_AR-mediated tonic currents recorded in rodent cerebellar granules cells can be modulated by ethanol in opposite directions in different strains exhibiting opposite preferences in alcohol consumption. These differences in ethanol sensitivity across strains are linked to differential levels of expression of presynaptic neuronal nitric oxide synthase and postsynaptic PKC activity.

How do dendrites contribute to neuronal computations in intact circuits? Using dual whole-cell recordings from the soma and dendrites of retinal ganglion cells, Sivyer and Williams demonstrate that the engagement and inhibitory synaptic control of a cascade of active dendritic integration compartments underlies the computation of image motion by direction-selective rabbit retinal ganglion cells—placing dendritic integration at the heart of physiologically engaged neuronal-circuit operation.

Cholinergic transmission from the basal forebrain provides neuromodulatory control over brain states such as wakefulness and sleep. Here the authors show that cholinergic input bidirectionally and dynamically modulates cortical processing of sensory inputs and influences visual perception in awake, behaving mice.

In this study, the authors show that, during the retinogeniculate refinement period, astrocyte-derived TGF-β regulates the expression and synaptic localization of C1q, a classical complement protein. They find that TGF-β signaling and C1q expression in neurons are key regulators of microglia-mediated synaptic pruning in the dorsal lateral geniculate nucleus.

The authors use dendritic imaging to examine odor response properties of individual synaptic sites of mushroom body neurons. They find that mushroom body neurons receive input from different glomerular channels and require several of those inputs to be co-active to spike, a likely foundation for their remarkable stimulus selectivity.

Adaptive control to improve performance after making mistakes in a given task is known to involve prediction error signaling in the anterior cingulate cortex (ACC). The current study examines adaptive control in humans and rats by using comparable time-estimation tasks for each organism, and the authors show that low-frequency oscillations within the ACC in humans and the medial frontal cortex (MFC) in rats are correlated with adaptive behavioral control. They also show that these frontal oscillations are phase locked to the oscillation in the motor regions in the brain and that inactivation of the MFC in rats can disrupt both behavioral control and oscillatory coupling.

In this study, the authors show that a subset of cerebellar granule neurons originate not from the granule neuron precursors (GNPs) but from a population of Nestin-expressing progenitors (NEPs) in the deep external germinal layer. In addition, they find that these NEPs are more susceptible to Sonic Hedgehog–induced genomic instability and tumor formation.

The authors study fMRI responses to colors and achromatic images to address the fundamental organizational principles of monkey inferior temporal cortex. They report color-biased regions adjacent and ventral to face patches, at locations predicted by a series of coarse eccentricity maps.