Articles in 2012

This study examines the phase response curves of gamma oscillations induced by carbachol or optogenetic stimulation in the hippocampal CA3 network. The authors report that distinct inputs differentially entrain the gamma oscillation in accordance with the relative drive to excitatory and inhibitory neurons in the circuit.

In this paper, the authors show that, in the non-diseased state, the huntingtin protein promotes homotypic interactions between neuroepithelial cells, a process that is critical for proper neurulation.

This study shows that spike timing–dependent depression between excitatory neurons requires endocannabinoid-mediated calcium signaling and glutamate release from nearby astrocytes, revealing that they are key elements in cortical plasticity.

The authors conduct simultaneous recording and optogenetic silencing of PV or SOM interneurons in the CA1 region of the hippocampus in head-fixed mice actively moving a treadmill belt. They report that these interneurons have distinct roles in controlling the rate, burst and timing of hippocampal pyramidal cells.

Cytosolic Ca²⁺ is known to control the gain and sensitivity of signaling in the olfactory sensory neurons (OSNs) through several molecular mechanisms. Here the authors find that mitochondrial Ca²⁺ mobilization is another critical component of OSN neuronal function, ensuring a broad dynamic response range and maintaining the sensitivity of the spike generation machinery.

Dendrites from the same neuron avoid each other through a mechanism involving cell surface proteins that trigger mutual repulsion. Here the authors show that the soluble axon guidance cue Netrin (UNC-6) drives sister dendrite self-avoidance in the PVD nociceptive neuron in C. elegans.

The engulfment receptor Draper is known to promote glial clearance of degenerating neurons in Drosophila, and this action of Draper is mediated by Src kinase. This study now shows that one of three Draper isoforms, namely Draper-II, negatively regulates glial clearance and acts in opposition to pro-clearance Draper-I.

The authors show that the SNARE protein VAMP4 acts to maintain calcium-dependent asynchronous synaptic vesicle release. These findings suggest that VAMP4 is functionally distinct from synaptobrevin2, which primarily drives fast, synchronous release.

It has been proposed that the center-surround receptive fields encountered in the early visual system serve to reduce the redundancy that is always present in natural scenes. The authors test this idea by recording from salamander retinal ganglion cells. They find strong decorrelation that is primarily a result of non-linear processing in the retina, rather than center-surround interactions. These nonlinearities serve to enhance efficient coding in the presence of noise.

In this study, the authors show that NgR1 and NgR3 can act as functional receptors for chondroitin sulfate proteoglycans (CSPGs), mediating inhibition of axonal growth and regeneration. This suggests a convergent mechanism for CSPG- and myelin-associated inhibitor activities after axonal injury in the CNS.

Using a combination of fMRI in humans and computational modeling, the authors show that different striatal nuclei encode different kinds of decision-making information. The anterior caudate nucleus encodes the value of individual steps in a decision tree, whereas the putamen encodes values learnt during extensive training.

Using optogenetic and physiological imaging tools, Busch et al. show that C. elegans sensory neurons that detect ambient oxygen concentration are tonic receptors and modify behavior in a persistent manner.

The authors show that the voltage-dependent proton channel Hv1 is required for NADPH oxidase (NOX)-dependent generation of reactive oxygen species in microglia in mice. Hv1^−/− mice were protected from NOX-mediated neuronal death and brain damage in a model of ischemia.

Following axonal injury in C. elegans, the growth factor SVH-1 and its cognate receptor tyrosine kinase, SVH-2, act to promote axonal regeneration via activation of the JNK-MAPK pathway.

This study describes the properties of dendritic electrogenesis in rat hippocampal CA3 pyramidal neurons and distinguishes the functional differences between proximal dendrites and distal dendrites, which receive differential inputs from the mossy fibers and the perforant pathways, respectively.

The authors show that the type-1 cannabinoid receptor (CB₁) is present in mouse neuronal mitochondrial membranes. They show that mitochondrial CB₁ receptors regulate cellular respiration and energy production in the brain and may contribute to synaptic plasticity in the hippocampus.

Inhibition of Bcl-2 and Bcl-x_L by ABT-737 is known to enhance tumor cell death. Here the authors find that it is actually protective against neuronal death in an animal model of ischemia via blockade of Bcl-x_L–induced mitochondrial channel activity. These findings point to Bcl-x_L as a potential therapeutic target.

The death of oligodendrocytes has been hypothesized to trigger the anti-myelin immunity observed in multiple sclerosis. In a mouse model, the authors show that diffuse oligodendrocyte death alone or in conjunction with immune activation does not initiate any anti-CNS immunity.

In this report, the authors demonstrate unique membrane potential dynamics of somatostatin-expressing (SOM) GABAergic neurons in layer 2/3 primary somatosensory barrel cortex of awake behaving mice. SOM neurons hyperpolarized and reduced action potential firing rates during sensorimotor processing, thereby reducing dendritic inhibition in nearby excitatory neurons during active neocortical computation.

Aversive long-term memory is formed after multiple conditioning sessions spaced by a rest interval. The authors identify specific dopaminergic neurons that display oscillatory calcium activity and are required during the rest interval to allow the formation of long-term memory in the mushroom body, the olfactory memory center.