Articles in 2012

The authors show that chronic treatment with antipsychotic drugs decreases expression of mGlu2 and histone acetylation at its promoter in frontal cortex. This is mediated through 5-HT2A receptor–dependent upregulation of HDAC2. HDAC inhibitors prevent this decrease in mGluR2, augmenting the behavioral effects of antipsychotics.

The Drosophila proteins Neuroligin (Nlg1) and Neurexin (Nrx-1) form a trans-synaptic complex that regulates synapse formation at the neuromuscular junction. Here the authors show that Syd-1, also known to regulate active zone formation, interacts with presynaptic Nrx-1, promoting synaptic clustering and immobilization of Nrx-1, and subsequent glutamate receptor incorporation.

Using juxtacellular recording and labeling of hippocampal interneurons in drug-free and behaving rats, the authors show that parvalbumin-expressing basket interneurons fire in a behavioral state–dependent manner, in contrast with neuropeptide Y– and nitiric oxide synthase–expressing ivy cells.

Humans and other animals can learn from errors of other individuals. Here, using two paired monkeys monitoring each other's action for their own action selection, the authors identify neurons in the medial frontal cortex (MFC) that have activity correlated with another's errors. This suggests that the MFC could contribute to monitoring others' mistakes.

This study describes how interactions between DOCK7 and TACC3 are key to the switch from proliferation to differentiation in developing radial glial progenitor cells (RGCs). DOCK7 exerts its effects via interactions with the centrosome-associated protein TACC3, and these interactions are likely to modulate the RGCs' apically directed interkinetic nuclear migration.

In this study, the authors show that two K⁺ channels, SK3 and GIRK, are important for the pheromone-induced activation of olfactory neurons in the vomeronasal organ (VNO). In addition, they show that K⁺ ion concentrations are maintained at high levels in the VNO lumen, permitting inward K⁺ flux through these channels.

Using simultaneous electrophysiological and optical imaging, this study finds that it is the linear summation of stimulus-independent trial-related and stimulus-dependent components that yield the signal seen in neuroimaging studies. However, the trial-related component, which does not correlate with neural spiking or LFPs, can account for over half of the neuroimaging signal, suggesting that it is crucial to take this component into account when interpreting neuroimaging studies.

The authors found that, when monkeys detected a salient stimulus defined purely by bottom-up factors, neurons in the dorsolateral prefrontal cortex represented the stimulus no later than those in the posterior parietal cortex. The results suggest an early involvement of the prefrontal cortex in the bottom-up guidance of visual attention.

Here the authors show that the binding of amyloid-β (Aβ) oligomers to cellular prion protein (PrPc) activates Fyn kinase. Aβ stimulation of PrPc/Fyn signaling drives phosphorylation of the NR2B subunit of NMDA receptors, with a subsequent loss of receptor surface expression and dendritic spines.

Using a novel spatial discrimination task, Bannerman and colleagues show that mice lacking hippocampal NMDA receptors in dentate gyrus and CA1 can encode and store spatial memories normally but fail to use this spatial knowledge to select appropriate responses from ambiguous choices.

In this study, the authors show that neocortical neural precursor cells exhibit progressively condensed chromatin as they lose neurogenic potential during development. Furthermore, the open chromatin state of early stage progenitors is regulated by the high mobility group A (HMGA) proteins.

In this study, the authors show that spontaneous calcium spiking activity in thalamocortical neurons modulates the rate of axonal growth during development via regulation of Robo1 transcription.

This study describes burst-dependent protection from synaptic depression, which maintains responsiveness to behaviorally important stimuli in Aplysia. In this attention-like mechanism, PKC at sensory neuron synapses discriminates the precise pattern of firing, preventing these release sites from becoming silenced during repeated tactile stimuli when these stimuli are salient.

By tracking brain activity in both normal subjects and in epilepsy patients, the authors demonstrate that there are differences in the time courses of activation to a memory task in the perirhinal cortex and the hippocampus. These results suggest differentiated roles for these two areas during memory tasks.

The authors show that the microRNA miR-7a fine-tunes the expression of the transcription factor Pax6, generating a dorsal-ventral gradient that controls differentiation of olfactory bulb precursors into dopaminergic neurons.

This paper reports that hippocampal theta sequences and their corresponding spatial paths stretch forward or backward as a function of an animal's behavior and that these firing sequences map the environment in segments of variable lengths or 'chunks'.

During Wallerian degeneration of Drosophila axons, Draper and Crk/Mbc/dCed-12 signaling non-redundantly promote clearance of axonal debris. Draper signaling is required early to activate glial responses to axonal injury, whereas Crk/Mbc/dCed-12 are dispensable for glial activation, but are essential at the phagocytic step for internalization and degradation of axonal debris.

Temporal regulation of embryonic neurogenesis is controlled by hypostable transcription factors. Here the authors show that the RNase III Drosha and DGCR8/Pasha, key components of the microRNA (miRNA) microprocessor, have important functions in mouse neurogenesis. Their results suggest direct and miRNA-independent destabilization of proneural mRNAs by the microprocessor.

This study uses single-channel current measurements, synaptic vesicle fusion–induced capacitance changes and structural modeling of the calyx of Held terminals to show that voltage-dependent calcium channel density at the active zone is a major determinant for the properties of neurotransmitter release and short-term synaptic plasticity.

Using functional and morphological analysis, this study demonstrates that in CA3 pyramidal cell recurrent axon terminals, the release probability and the number of voltage-gated calcium channels are linearly correlated with the size of the active zone.