Articles in 2009

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  • The amyloid beta (Aβ) peptide has been implicated in the pathogenesis of Alzheimer's disease. The authors report that overproduction of axonal or dendritic Aβ in rat organotypic slices reduces spine density and plasticity at nearby dendrites. Aβ production is dependent on action potentials and nicotinic receptors, whereas the effects of Aβ are dependent on NMDA receptors.

    • Wei Wei
    • Louis N Nguyen
    • Roberto Malinow
    Article
  • The authors detect cytosolic histone deacetylase-1 (HDAC1), a nuclear transcriptional repressor, in damaged axons in brains of humans with multiple sclerosis and of mice with cuprizone-induced demyelination. They show a cytotoxic mechanism in which the exported HDAC1 impairs mitochondrial transport, independent of its nuclear function.

    • Jin Young Kim
    • Siming Shen
    • Patrizia Casaccia
    Article
  • It remains controversial whether the neocortex harbors progenitors that are capable of neurogenesis in vivo. Here the authors show that there is a population of mitotic cells in cortical layer I that are activated after ischemia to proliferate and generate GABAergic neurons.

    • Koji Ohira
    • Takahiro Furuta
    • Shun Nakamura
    Article
  • Recording from hippocampal slices, the authors find that brief stimulation triggers long-lasting synaptic barrages in mossy cells and hilar interneurons that arise from persistent firing in semilunar granule cells. Transient stimulation of different entorhinal cortex pathways activated distinct assemblies of hilar neurons, representing a previously unknown mechanism of short-term information storage that persisted for up to 10 seconds.

    • Phillip Larimer
    • Ben W Strowbridge
    Article
  • The authors use chromophore-targeted laser photolysis to selectively kill pyramidal neurons that project from auditory cortex to the inferior colliculus. They find that this eliminates the experience-dependent recalibration of sound localization, while leaving normal sound localization intact, implicating this pathway in learning-induced plasticity.

    • Victoria M Bajo
    • Fernando R Nodal
    • Andrew J King
    Article
  • Selecting relevant information to make perceptual judgements is usually thought to be a cortical function. By reversibly deactivating the superior colliculus in monkeys, this study demonstrates that activity in a subcortical structure can also inform perceptual judgements, even in the absence of orienting movements (a function previously attributed to the superior colliculus).

    • Lee P Lovejoy
    • Richard J Krauzlis
    Article
  • People and animals are capable of making decisions using information about the probabilistic associations between a combination of cues and an outcome. Here the authors use computational theory to suggest that the posterior ratio, an important quantity for forming probabilistic inferences, can be learned and encoded by synapses that have bounded weights and undergo reward-dependent Hebbian plasticity.

    • Alireza Soltani
    • Xiao-Jing Wang
    Article
  • In rodents, descending corticospinal tracts can be rerouted to innervate new targets after a spinal cord injury. Here, Ghosh et al. show that such anatomical rearrangement in the injured spinal cord is accompanied by sensory remapping at the cortical level.

    • Arko Ghosh
    • Florent Haiss
    • Martin E Schwab
    Article
  • Mammalian cochlea inner hair cells (IHCs) can code a continuous grading of sound intensities. This is because neurotransmitter release at mature sensory ribbon synapses is linearly dependent on calcium influx, which has the effect of broadening the cells' dynamic range. Immature IHC neurotransmitter release is quite different. Here, the authors show that a switch from syanptogamin I and II to synaptogamin IV underlies this developmental change.

    • Stuart L Johnson
    • Christoph Franz
    • Walter Marcotti
    Article
  • Information flow in the cortex is usually thought to be subserved by direct, cortico-cortical connections. Using optical imaging in a thalmocortical slice preparation, this study demonstrates a potent corticothalamocortical pathway from layer 5 of the S1 barrel field to S2 of the mouse somatosensory cortex.

    • Brian B Theyel
    • Daniel A Llano
    • S Murray Sherman
    Article
  • Recording from single neurons in awake macaque monkeys, the authors find that neurons of the frontal pole cortex encode decisions at the time of feedback, but do not carry signals typically seen in other prefrontal areas, such as information about sensory cues, strategies, working memory, future goals or movement plans.

    • Satoshi Tsujimoto
    • Aldo Genovesio
    • Steven P Wise
    Article
  • The authors report that the spiking history of small, randomly sampled ensembles of human and nonhuman primate cortical neurons can predict subsequent single neuron spiking. Spiking could be predicted by both local ensemble spiking histories as well as those in other cortical areas. These results provide evidence for strong collective cortical dynamics at the level of neuronal spikes.

    • Wilson Truccolo
    • Leigh R Hochberg
    • John P Donoghue
    Article
  • To keep track of input and output over a course of time, generation of rhythmic neuronal activity requires a form of spike counter. In this study, Pulver and Griffith show that electrogenic activity of Na+/K+ pump underlies afterhyperpolarization in Drosophila larval motor neuron, which can functions as an activity integrator and as an intrinsic mechanism of cellular short-term memory.

    • Stefan R Pulver
    • Leslie C Griffith
    Article
  • Simple cell receptive fields (RFs) consist of spatially segregated 'On' and 'Off' subregions. Previous work suggested that excitatory inputs underlie this segregation. This study uses voltage clamp recordings in mouse to reveal that actually inibitory inputs are responsible for RF organization.

    • Bao-hua Liu
    • Pingyang Li
    • Huizhong Whit Tao
    Article
  • Axonal pathfinding during development needs appropriate responses to various attractive and repulsive guidance cues. The exact mechanisms by which different attractant/repulsion machineries interact or how the switch is precisely regulated at appropriate location are unknown. Here, Parra and Zou find that Sonic Hedgehog (Shh) can turn on Semaphorin repulsion via Shh receptors Patched-1 and Smoothened via the PKA pathway.

    • Liseth M Parra
    • Yimin Zou
    Article