Research articles

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.

This study shows that neural progenitor cells in the adult hippocampus of mice receive immature GABAergic synaptic inputs from parvalbumin (PV)-expressing interneurons, and uses optogenetic stimulation to demonstrate local PV interneuron activation via GABA signaling promotes survival and maturation of newborn neurons.

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.

In this paper the authors demonstrate that functionally independent populations of neurons in the ventromedial hypothalamus (VMH), a region implicated in feeding, sex, and aggression, are essential for predator and social fear in mice.

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.

In this study, the authors show that the mouse ortholog of the amyotropic lateral sclerosis/frontotemporal dementia (ALS/FTD)-associated human locus C9ORF72 exhibits highly enriched expression in the neuronal cell types that show susceptibility during the disease. These findings suggest a potential explanation for the cell selectivity observed in ALS/FTD.

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.

Here the authors show that optogenetic stimulation of Purkinje cells, the sole output neurons of the cerebellar cortex, can drive motor learning in mice. This represents an additional instructive signal for the induction of learning, beyond climbing fibers, that can expand the learning capacity of motor circuits.

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 Resource study, the authors used Direct RNA Sequencing (DRS) to quantitatively examine the transcriptional profile of microglia, focusing specifically on the proteins important for binding endogenous ligands and potential pathogens—a collection they term the 'sensome'. They also compare this profile to that of peripheral macrophages.

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.