Articles in 2012

Thalamic activity is strongly inhibited by pallidal inputs from the basal ganglia, but the role of excitatory inputs from cortex is unclear. Recording from presynaptic pallidal axon terminals and connected postsynaptic thalamocortical neurons in zebra finches, the authors find that pallidal inputs control thalamic spike timing, whereas cortical inputs may be the principle drivers of thalamic activity during singing.

This study uncovers a previously unknown function of Slit2, a known axonal guidance molecule, and Robo receptors in regulating fasciculation of motor axons during muscle target innervation.

The authors describe the role of the primary cilium in the synaptic integration of adult-born hippocampal neurons. Preventing cilia formation in adult-born neurons causes deficits in dendritic refinement and synaptic formation.

In this study, the authors direct human iPS and ES cells to adopt cortical progenitor and, subsequently, mature projection neurons with functional synaptic connections. This protocol is able to generate both deep and upper layer neurons in proper temporal order.

This review article discusses the basis of β-amyloid's contribution to Alzheimer's disease pathology and critically examines the toxic Aβ oligomer hypothesis.

Slit and NTRK-like family member (Slitrk) proteins are known to have typical peptide signatures for synaptogenic cell adhesion. This study reveals a specific function of Slitrk3 and tyrosine phosphatase receptor PTPδ transynaptic interaction in inhibitory synaptogenesis and excitatory and inhibitory balance.

Using direct recordings in monkeys, the authors find that theta-band synchronization between V4 and prefrontal cortex is likely to be important for the maintenance of short-term visual memory. These synchronizations provide a means for distant cortical areas to communicate with each other during the performance of a cognitive task.

A mathematical model based on the dynamics of molecular signaling pathways predicts an optimal training regimen that enhances learning and memory.

A study uses light-gated ion channels to control the activity of neurons in each eye, thereby revealing how the timing of neuronal firing dictates whether visual circuits segregate from one another or stay mixed.

A knock-in mouse mimicking a MeCP2 mutation found in human Rett syndrome recapitulates disease features, including progressive motor and cognitive impairments—and correlations emerge between MeCP2 dosage in mice and phenotype.

Brain regions exhibit specialization for different functions, but such functions are constrained by anatomical connections to other brain regions. A study now finds that, by measuring these connections, we can predict complex functional responses before the subject has even performed the task.

Cell specification of olfactory receptor neurons in Drosophila is orchestrated by context-dependent response to Notch signaling mediated by Hamlet, which directs specific chromatin modifications in subsets of neurons.

This is a review of current advances in the genetics of substance use disorders (SUDs), discussing how both genetic and environmental sources of risk are required to develop a complete picture of SUD etiology.

Cortical states regulate behavior, but the network mechanisms underlying cortical states are unknown. Here the authors show that the desynchronized cortical state that occurs during active behavior is driven by an increase in thalamic firing independent of sensory input, which can be mimicked by optogenetic stimulation of the thalamus.

Using several lines of retinal cell type–specific GENSET BAC transgenic GFP mice, the authors segregated these retinal cell types then subjected them to transcriptome microarray analysis to provide a transcriptional 'barcode' of retinal cell identity.

Recording in the rat primary visual cortex, this study finds that after repeated exposure to a light spot moving along the same path, just seeing the static spot at its start position is sufficient to cause the sequence of activity associated with the movements of the spot along its path. This activity may contribute to cue-triggered recall of learned sequences.

This study shows that the interaction between metabotropic glutamate receptor 5 (mGluR5) and a specific form of the scaffolding protein Homer contributes to the behavioral and physiological defects in the mouse model of fragile X syndrome.

Here the authors review evidence suggesting that cocaine-induced changes in orbitofrontal cortex disrupt the representation of states and transition functions that form the basis of flexible behavioral control, resulting in reliance on less flexible control systems and consequently in the pattern of maladaptive behaviors associated with cocaine addiction.

The authors use optical activation and cell type–specific pharmacogenetic silencing in vitro to show that dendritic inhibition critically regulates input-output transformations in mouse hippocampal CA1 pyramidal cells. Dendrite-targeting interneurons are themselves modulated by interneurons targeting pyramidal cell somata.