Articles in 2012

In worms, male exploratory behavior is influenced by two competing needs, food and sex. In this paper, the authors highlight the importance of the pigment dispersing factor signaling pathway in the normal function of a gender-shared neuronal circuit that is involved male-specific reproductive drive.

In this study, the authors used two-photon imaging in macaque monkey to show that orientation and spatial frequency maps are intimately related at a fine spatial scale. They find that the map gradients have a striking tendency toward orthogonality and co-vary negatively from cell to cell at the spatial scale of cortical columns.

The authors assessed the contributions of early life stress (ELS) and childhood cortisol levels to adolescent resting-state functional connectivity. In females, ELS predicted increased cortisol levels in childhood, which predicted decreased amygdala-ventromedial prefrontal cortex (vmPFC) functional connectivity. Amygdala-vmPFC connectivity was inversely correlated with anxious sympotms and positively correlated with depressive symptoms.

The authors use a computational approach (NETBAG+) to integrate and analyze diverse genetic data and apply this to study schizophrenia-associated genetic variations. They identify gene networks related to axon guidance, synaptic function, cell mobility and chromosomal remodeling.

Ubiquitin proteasome system–mediated, neuronal activity–dependent protein turnover at synapses often occurs in an ensemble fashion where a group or groups of postsynaptic density (PSD) proteins are degraded together in a homeostatic response. This study shows that the synaptic level of the PSD scaffolding protein called GKAP (also known as SAPAP1) is bidirectionally regulated in a homeostatic fashion and is mediated by differential phosphorylation by CaM kinase II isoforms.

In this study, the authors report that a focal cortical injury can induce changes in the excitability of thalamocortical neurons that contributes to the maintenance of cortical seizures. In addition, silencing these neurons via a closed-loop optogenetic approach is sufficient to interrupt these seizures.

In this study, the authors show that Hox5 genes are essential for the organization, survival and axonal branching of motor neurons required for breathing. Unexpectedly, this requirement for Hox5 activity persists to later developmental stages.

This study uses EEG in humans to isolate and track an evolving, domain-general decision signal, which varies with accumulated evidence, but is independent of overt actions.

The authors explore how sensory maps are reshaped by experience in vivo, using chronic two-photon calcium imaging to follow whisker-evoked activity of individual layer 2/3 neurons in adult mouse barrel cortex over weeks. By first measuring activity with whiskers intact and then with continued trimming of all but one whisker, they describe how the redistribution of population activity underlies large-scale cortical remapping.

Different types of bipolar cells in the retina carry distinct visual signals to select types of amacrine cells and ganglion cells. The authors show that a single bipolar cell can evoke distinct responses in different ganglion cells and that this signal divergence is the result of interactions with amacrine cells.

Dopamine signaling is known to influence sleep and arousal in Drosophila. Here the authors identify the circuitry underlying the effect of dopamine on arousal, which involves D1 dopamine receptors in the dorsal fan-shaped body as the target of dopaminergic projections.

Using a knock-in strategy to ablate a Cdk5-targeted serine phosphorylation site on residue 478 of the TrkB receptor, the authors demonstrate the role of this phosphorylation in activity-dependent functional and structural plasticity, as well as in learning and memory. They further show that TIAM1 and Rac1 act downstream of TrkB S478 phosphorylation during spine remodeling.

GPR88 is an orphan G protein–coupled receptor expressed in striatal medium spiny neurons (MSNs). The authors show that deletion of Gpr88 in mice leads to hyperactivity, poor motor coordination and impaired cue-based learning. MSNs lacking GPR88 show increased excitation and reduced inhibition in vitro, and enhanced firing rates in vivo.

Persistent activity can mediate working memory during behavior. Here, the authors report persistent activity during sleep, occurring spontaneously in medial entorhinal cortex layer III (MECIII) neurons' membrane potential. This persistent activity excited hippocampal CA1 neurons. Thus, persistent activity in MECIII contributes to cortico-hippocampal interaction, which could serve several important mnemonic functions.

The authors selectively target a population of hippocampal interneurons called oriens lacunosum-moleculare (OLM) cells with the Chrna2 promoter to demonstrate that these cells differentially modulate CA3 and entorhinal inputs to CA1 pyramidal cells. They also find that OLM cells receive fast cholinergic inputs, providing a plausible explanation for how nicotine affects hippocampal plasticity.

Moving objects generate motion information at different scales, but it is not known how the brain pools all of this information to reconstruct object speed and whether pooling depends on the purpose for which the information will be used. Here the authors find task-dependent differences in pooling that can be explained by an adaptive gain control mechanism.

In this study, the authors compare the RNA binding patterns of FUS/TLS and TDP-43. Although these proteins regulate the processing of mostly distinct gene products, they do show concurrent regulation of a subset of neuronal transcripts that all have exceptionally long introns.

The authors previously showed that a minority of nucleus accumbens neurons, which show strong cocaine-induced activation of the immediate early gene Fos, are necessary for cocaine-induced psychomotor sensitization. Here they find that these cocaine-activated neurons have increased numbers of silent synapses following cocaine sensitization.

The authors show, for human observers, that glossy surfaces can generate both bright specular highlights and dark specular 'lowlights' and that the presence of either is sufficient to generate compelling percepts of gloss. These results suggest that the image structure generated by specular highlights and lowlights is used to construct our experience of surface gloss.

The authors attempt to improve existing retinal models by incorporating measurements of the physiological properties and connectivity of only the primary excitatory circuitry of the retina. The resulting model predicts ganglion cell responses to a variety of spatial patterns and provides a direct correspondence between circuit connectivity and retinal output.