Articles

Rapid vesicle exocytosis requires the Ca²⁺ sensor synaptotagmin I (syt). Here the AUs manipulate the length and rigidity of the linker connecting the two Ca²⁺ sensing domains of syt. This revealed a set of intra-molecular interactions that determined the ability of the domains to penetrate membranes and drive evoked transmitter release in response to Ca²⁺.

Here the authors report that repeated presentations of a visual sequence over a course of days causes evoked response potentiation in mouse V1 that is highly specific for stimulus order and timing. After V1 is trained to recognize a sequence, cortical activity regenerates the full sequence even when individual stimulus elements are omitted.

Much of what we know about the signal transduction machinery of the canonical Wnt pathway comes from studying the colon, where low- versus high-activity Wnt signaling states are known to distinguish normal colon epithelium turnover from colorectal cancer. Here, Fancy et al. demonstrate that a pathological Wnt activity state akin to that in colon cancer exists in oligodendrocyte precursor cells in human neonatal white matter injury, which leads to detrimental maturation arrest of these cells. These oligodendrocyte precursors in human newborn brain injury express multiple genes in common with colon cancer, demonstrating a pathological Wnt tone in non-genetic human disease.

Here, using magnetoencephalography, the authors show that in humans, neural events locked to heartbeats before stimulus onset predict the detection of a faint visual grating in the posterior right inferior parietal lobule and ventral anterior cingulate cortex, two regions with multiple functional correlates that belong to the same resting-state network.

The subjective values of stimuli can be changed through reward-based learning, but here the authors show that the value of food items can be modulated by the concurrent presentation of an irrelevant auditory cue to which subjects must make a motor response. The effects of this pairing lasted at least 2 months, and neuroimaging revealed increased preference-related activity in ventromedial prefrontal cortex.

In this study, the authors identify a population of deep dorsal horn interneurons that receive inputs from both sensory neurons and the descending motor tracts and that can evoke activity from functionally related motor pools. These cells may represent the central node for coordinating motor output programs in the spinal cord.

Changes in brain gene expression by cocaine are known to involve epigenetic machineries. The histone methyltransferase G9a is a mediator of cocaine-induced structural and behavioral plasticity in the nucleus accumbens of mouse. This study finds cocaine-induced, G9a-mediated gene repression in both direct and indirect pathway medium spiny neurons (MSNs). The study also uses cell type–specific overexpression and conditional knockout of G9a in each MSN cell type and shows that G9a influences the developmental specification of striatal MSN subtypes, which in turn affects behavioral response to cocaine.

In this study, the authors show that cell-autonomous expression of mutant Huntingtin in microglia can elicit alterations in the transcriptional profile and activation state of the cells. In particular, there is an upregulation of pro-inflammatory and myeloid lineage factors and an increased ability to promote neuronal death after inflammatory insult.

Simultaneous performance of two tasks often leads to deficits in the component tasks, an effect thought to depend on the lateral prefrontal cortex (LPFC). Here, the authors recorded single-neuron activities in monkey LPFC during two simultaneous tasks, providing direct neurophysiological evidence for models of dual-task interference and capacity limitation.

The authors recorded from granule cells (GCs) in the main olfactory bulb of anesthetized and awake mice. Odor responses in GCs of awake mice were more robust and broadly tuned than under anesthesia. Unlike in anesthetized mice, odor coding in GCs in awake mice was not coupled to the respiratory cycle.

Astrocytes provide essential support for and modulate synaptic transmission between neurons. Here the authors show that non-channel functions of connexin 30, a gap-junction subunit, control the synaptic coverage of astroglial processes and regulate glutamate clearance, synaptic strength and memory function.

The authors show that rostral ventral pallidum projections to the ventral tegmental area (VTA) are activated during cue-induced reinstatement of cocaine seeking, and DREADD inhibition of these projections blocks this behavior. In contrast, projections from the caudal ventral pallidum are necessary for cocaine-primed, but not cue-induced, reinstatement of cocaine seeking.

This study shows that activity-dependent palmitoylation of δ-catenin stabilizes the cell adhesion molecule N-cadherin at the excitatory synapse and that this post-translational modification is important for GluA1- and GluA2-mediated synaptic and structural plasticity.

In this study, the authors show that there are multiple forms of opioid-induced long-term depression (OP-LTD) in the dorsal striatum, each mediated by the mu, delta or kappa opioid receptor. The mu and delta OP-LTD are presynaptic and can summate, but only mu OP-LTD occludes endocannabinoid-induced LTD. Furthermore, mu OP-LTP, but not kappa or delta OP-LTP, is blocked by the analgesic oxycodone.

The authors examine magnetoencephalographic recordings during relevant- and irrelevant-feature processing in a visual attention task. As participants attend to stimulus color or motion, a temporal sequence of relevant followed by irrelevant feature activations may bind an attended object's features into a unitary percept.

Sparse coding is thought to facilitate pattern separation for associative memory, but behavioral evidence is scant. The authors show that in Drosophila, feedback inhibition enforces sparse odor coding in Kenyon cells, the neurons that store olfactory associations. Disrupting this sparsening mechanism impairs learned discrimination of similar, but not dissimilar, odors.

Here the author shows that an unstructured, sparsely connected network of model spiking neurons can display two different types of asynchronous activity: one in which an external input leads to a highly redundant response of different neurons that favors information transmission and another in which the firing rates of individual neurons fluctuate strongly in time and across neurons to provide a substrate for complex information processing.

In this study, the authors show that altering the photoperiod of mice results in reversible transcriptional and DNA methylation changes in the suprachiasmatic nucleus. Application of a methyltransferase inhibitor blocks the light-entrained changes in the circadian period, suggesting that these methylation changes directly mediate circadian plasticity.

To adaptively navigate their environments organisms need to predict and cancel out the sensory consequences of their actions. Here the authors show that granule cells within the cerebellum-like structure of weakly electric fish have delayed responses that closely match the timing of self-generated sensory inputs. This enables corollary discharges to be transformed into negative images that are well-tuned to the animal's own behavior.

This study shows that activation of cannabinoid type-1 (CB1) receptors in the olfactory bulb increases odor detection and food intake in hungry mice. The authors show that this function is mediated by CB1-dependent attenuation of excitatory corticofugal synaptic transmission onto inhibitory granule cells and disinhibition of mitral cells in the main olfactory bulb.