Connecting the dots - p99

doi:10.1038/nn0209-99

Understanding the exact link between functional magnetic resonance imaging (fMRI) and neural activity is critical to bridge the widening gap between neuroimagers and cellular neuroscientists.

Full Text - Connecting the dots | PDF (210 KB) - Connecting the dots

Brain reflections - p101

Ullrich Wagner & Patrik Vuilleumier review Mirroring People by Marco Iacoboni

doi:10.1038/nn0209-101

Full Text - Brain reflections | PDF (138 KB) - Brain reflections

Making scents out of how olfactory neurons are ordered in space - pp103 - 104

Nathan E Schoppa

doi:10.1038/nn0209-103

Many sensory brain areas are characterized by a specific spatial organization, with neurons being ordered according to their similarity in receptive field properties. A surprising new study provides evidence that the organization of glomeruli in the olfactory bulb violates this anatomical principle, suggesting that olfaction might work by a different set of rules.

Full Text - Making scents out of how olfactory neurons are ordered in space | PDF (199 KB) - Making scents out of how olfactory neurons are ordered in space

See also: Article by Soucy et al.

Whither proBDNF? - pp105 - 106

Philip A Barker

doi:10.1038/nn0209-105

ProBDNF has been proposed to alter synaptic plasticity, but whether it is normally released from neurons has been a matter of contention. New work suggests that proBDNF is indeed secreted from central neurons.

Full Text - Whither proBDNF? | PDF (441 KB) - Whither proBDNF?

See also: Brief Communication by Yang et al.

Too much Sonic, too few neurons - pp107 - 108

Christopher A Fasano & Lorenz Studer

doi:10.1038/nn0209-107

The floor plate can generate neurons, but does so only in the midbrain. New work shows that Shh suppresses floor plate neurogenesis, and that in the midbrain, Wnt downregulates Shh expression via canonical signaling through -catenin.

Full Text - Too much Sonic, too few neurons | PDF (225 KB) - Too much Sonic, too few neurons

See also: Article by Joksimovic et al.

PML: a tumor suppressor essential for neocortical development - pp108 - 110

Karisa C Schreck & Nicholas Gaiano

doi:10.1038/nn0209-108

Brain development requires precise control of progenitor proliferation and differentiation. PML appears to be a crucial regulator of cortical progenitors, limiting proliferation and promoting the generation of committed neuronal precursors.

Full Text - PML: a tumor suppressor essential for neocortical development | PDF (267 KB) - PML: a tumor suppressor essential for neocortical development

See also: Article by Regad et al.

Sleep on it - p110

Charvy Narain

doi:10.1038/nn0209-110

Full Text - Sleep on it | PDF (113 KB) - Sleep on it

See also: Brief Communication by Van Der Werf et al.

Exit chloride, enter glutamate - pp111 - 112

Felix E Schweizer

doi:10.1038/nn0209-111

The in vitro reconstitution of vesicular glutamate transport reveals that the transporter itself antiports chloride ions and suggests that extracellular chloride concentrations may determine neurotransmitter refilling and quantal size.

Full Text - Exit chloride, enter glutamate | PDF (263 KB) - Exit chloride, enter glutamate

See also: Article by Schenck et al.

Neuronal release of proBDNF - pp113 - 115

Jianmin Yang, Chia-Jen Siao, Guhan Nagappan, Tina Marinic, Deqiang Jing, Kelly McGrath, Zhe-Yu Chen, Willie Mark, Lino Tessarollo, Francis S Lee, Bai Lu & Barbara L Hempstead

doi:10.1038/nn.2244

ProBDNF can have drastic effects on synaptic function that are quite different from those of mature BDNF. It is, however, controversial whether proBDNF is ever released in amounts that are sufficient to affect normal synaptic plasticity. Here, Yang and colleagues have detected the release of proBDNF from hippocampal neurons using newly developed knock-in mice and antibodies.

Abstract - | Full Text - Neuronal release of proBDNF | PDF (353 KB) - Neuronal release of proBDNF | Supplementary information

See also: News and Views by Barker

Laminar and compartmental regulation of dendritic growth in mature cortex - pp116 - 118

David K Chow, Matthias Groszer, Mochtar Pribadi, Michal Machniki, S Thomas Carmichael, Xin Liu & Joshua T Trachtenberg

doi:10.1038/nn.2255

The authors use chronic in vivo imaging to study pyramidal neurons before and after deletion of the tumor suppressor gene Pten in mature neurons of the mouse cortex. They find that Pten/mTOR signaling only regulates growth of layer 2/3 apical dendrites.

Abstract - | Full Text - Laminar and compartmental regulation of dendritic growth in mature cortex | PDF (405 KB) - Laminar and compartmental regulation of dendritic growth in mature cortex | Supplementary information

Collagen VI protects neurons against A toxicity - pp119 - 121

Jason S Cheng, Dena B Dubal, Daniel H Kim, Justin Legleiter, Irene H Cheng, Gui-Qiu Yu, Ina Tesseur, Tony Wyss-Coray, Paolo Bonaldo & Lennart Mucke

doi:10.1038/nn.2240

Cheng and colleagues propose a mechanism for amyloid- toxicity that may have relevance for Alzheimer's disease. They show that A1–42 induces expression of collagen VI and that collagen VI protects against A toxicity in cultured neurons.

Abstract - | Full Text - Collagen VI protects neurons against A toxicity | PDF (396 KB) - Collagen VI protects neurons against A toxicity | Supplementary information

Sleep benefits subsequent hippocampal functioning - pp122 - 123

Ysbrand D Van Der Werf, Ellemarije Altena, Menno M Schoonheim, Ernesto J Sanz-Arigita, José C Vis, Wim De Rijke & Eus J W Van Someren

doi:10.1038/nn.2253

This study finds that reducing the amount of slow-wave sleep results in worse performance on a subsequent memory test and reduced encoding-related hippocampal fMRI activation. This happens even though the total amount of sleep was unaffected, suggesting that hippocampus-dependent memory is particularly affected by shallow sleep.

Abstract - | Full Text - Sleep benefits subsequent hippocampal functioning | PDF (200 KB) - Sleep benefits subsequent hippocampal functioning | Supplementary information

See also: News and Views by Narain

Wnt antagonism of Shh facilitates midbrain floor plate neurogenesis - pp125 - 131

Milan Joksimovic, Beth A Yun, Raja Kittappa, Angela M Anderegg, Wendy W Chang, Makoto M Taketo, Ronald D G McKay & Rajeshwar B Awatramani

doi:10.1038/nn.2243

The floor plate is not usually a neurogenic structure, but in the embryonic midbrain, dopaminergic neurons do develop from floor plate. This study shows that the high levels of Shh that are present in the floor plate generally suppress neurogenesis and that for neurons to be generated, Shh must be downregulated by Wnt signaling in the midbrain.

Abstract - | Full Text - Wnt antagonism of Shh facilitates midbrain floor plate neurogenesis | PDF (1,054 KB) - Wnt antagonism of Shh facilitates midbrain floor plate neurogenesis | Supplementary information

See also: News and Views by Fasano & Studer

The tumor suppressor Pml regulates cell fate in the developing neocortex - pp132 - 140

Tarik Regad, Cristian Bellodi, Pierluigi Nicotera & Paolo Salomoni

doi:10.1038/nn.2251

This work shows that the transcriptional modulator and tumor suppressor Pml functions in embryonic nestin-positive cortical progenitor cells to regulate protein phosphatase 1, leading to dephosphorylation of pRb, reduction of mitosis and increased neurogenesis.

Abstract - | Full Text - The tumor suppressor Pml regulates cell fate in the developing neocortex | PDF (1,406 KB) - The tumor suppressor Pml regulates cell fate in the developing neocortex | Supplementary information

See also: News and Views by Schreck & Gaiano

Identification of distinct telencephalic progenitor pools for neuronal diversity in the amygdala - pp141 - 149

Tsutomu Hirata, Peijun Li, Guillermo M Lanuza, Laura A Cocas, Molly M Huntsman & Joshua G Corbin

doi:10.1038/nn.2241

Fate-mapping the cells that express the homeodomain transcription factor Dbx1 in the developing mouse brain, this study finds that the preoptic area is a previously unknown source of inhibitory amygdala neurons. In contrast, excitatory amygdala neurons are shown to develop from Dbx1-positive cells in the ventral pallium.

Abstract - | Full Text - Identification of distinct telencephalic progenitor pools for neuronal diversity in the amygdala | PDF (1,157 KB) - Identification of distinct telencephalic progenitor pools for neuronal diversity in the amygdala | Supplementary information

UNC-129 regulates the balance between UNC-40 dependent and independent UNC-5 signaling pathways - pp150 - 155

Lesley T MacNeil, W Rod Hardy, Tony Pawson, Jeffrey L Wrana & Joseph G Culotti

doi:10.1038/nn.2256

In the worm, netrin and the TGF-related molecule UNC-129 form opposing dorsoventral gradients. Motor axons are repelled by netrin and attracted to UNC-129, but no TGF receptors appear to be involved in the attraction. This study shows that UNC-129 enhances repulsive signaling from the netrin receptor complex UNC-5/UNC-40, via a direct interaction with UNC-5.

Abstract - | Full Text - UNC-129 regulates the balance between UNC-40 dependent and independent UNC-5 signaling pathways | PDF (548 KB) - UNC-129 regulates the balance between UNC-40 dependent and independent UNC-5 signaling pathways | Supplementary information

A chloride conductance in VGLUT1 underlies maximal glutamate loading into synaptic vesicles - pp156 - 162

Stephan Schenck, Sonja M Wojcik, Nils Brose & Shigeo Takamori

doi:10.1038/nn.2248

Glutamate loading of synaptic vesicles requires moderate Cl^- concentrations, but is inhibited by high Cl^-. Here, Schenck et al. show that the glutamate transporter VGLUT1 is itself a chloride channel. Although high extravesicular Cl^- inhibited glutamate import through a competitive mechanism, high intravesicular Cl^- concentrations enhanced glutamate import. This suggests that, in addition to the pH gradient, VGLUT1 can also utilize a steep Cl^- gradient to drive glutamate transport.

Abstract - | Full Text - A chloride conductance in VGLUT1 underlies maximal glutamate loading into synaptic vesicles | PDF (518 KB) - A chloride conductance in VGLUT1 underlies maximal glutamate loading into synaptic vesicles | Supplementary information

See also: News and Views by Schweizer

Synaptotagmin IV: a multifunctional regulator of peptidergic nerve terminals - pp163 - 171

Zhenjie Zhang, Akhil Bhalla, Camin Dean, Edwin R Chapman & Meyer B Jackson

doi:10.1038/nn.2252

The function of Synaptotagmin IV (Syt IV) in vesicle exocytosis and neurotransmitter release is debated, as Syt IV does not bind calcium. Here, Zhang et al. show that Syt IV localizes to the vesicles of neuropeptide-secreting nerve terminals in the posterior pituitary and regulates the kinetics of calcium-triggered exocytosis.

Abstract - | Full Text - Synaptotagmin IV: a multifunctional regulator of peptidergic nerve terminals | PDF (2,864 KB) - Synaptotagmin IV: a multifunctional regulator of peptidergic nerve terminals | Supplementary information

A critical role for PSD-95/AKAP interactions in endocytosis of synaptic AMPA receptors - pp172 - 181

Samarjit Bhattacharyya, Virginie Biou, Weifeng Xu, Oliver Schlüter & Robert C Malenka

doi:10.1038/nn.2249

The endocytosis of AMPA receptors underlies several forms of synaptic plasticity. Here, the authors show that PSD-95, via its binding to AKAP150, is important for NMDAR-triggered endocytosis of synaptic AMPARS.

Abstract - | Full Text - A critical role for PSD-95/AKAP interactions in endocytosis of synaptic AMPA receptors | PDF (1,966 KB) - A critical role for PSD-95/AKAP interactions in endocytosis of synaptic AMPA receptors | Supplementary information

N-Acetylcysteine reverses cocaine-induced metaplasticity - pp182 - 189

Khaled Moussawi, Alejandra Pacchioni, Megan Moran, M Foster Olive, Justin T Gass, Antonieta Lavin & Peter W Kalivas

doi:10.1038/nn.2250

The authors report that rats that were withdrawn from cocaine self-administration had an in vivo deficit in their ability to develop long-term potentiation and depression in the nucleus accumbens core following prefrontal cortex stimulation. N-acetylcysteine, a drug that prevents relapse, restored the ability to induce plasticity.

Abstract - | Full Text - N-Acetylcysteine reverses cocaine-induced metaplasticity | PDF (718 KB) - N-Acetylcysteine reverses cocaine-induced metaplasticity | Supplementary information

Dopamine modulates an mGluR5-mediated depolarization underlying prefrontal persistent activity - pp190 - 199

Kyriaki Sidiropoulou, Fang-Min Lu, Melissa A Fowler, Rui Xiao, Christopher Phillips, Emin D Ozkan, Michael X Zhu, Francis J White & Donald C Cooper

doi:10.1038/nn.2245

Individual prefrontal cortex neurons can exhibit persistent activity during a delay between a cue and a behavioral response. Here the authors report on an mGluR5-mediated depolarization that underlies persistent activity and is sensitive to both dopamine and cocaine.

Abstract - | Full Text - Dopamine modulates an mGluR5-mediated depolarization underlying prefrontal persistent activity | PDF (834 KB) - Dopamine modulates an mGluR5-mediated depolarization underlying prefrontal persistent activity | Supplementary information

CREB regulation of nucleus accumbens excitability mediates social isolation–induced behavioral deficits - pp200 - 209

Deanna L Wallace, Ming-Hu Han, Danielle L Graham, Thomas A Green, Vincent Vialou, Sergio D Iñiguez, Jun-Li Cao, Anne Kirk, Sumana Chakravarty, Arvind Kumar, Vaishnav Krishnan, Rachael L Neve, Don C Cooper, Carlos A Bolaños, Michel Barrot, Colleen A McClung & Eric J Nestler

doi:10.1038/nn.2257

cAMP response element–binding protein (CREB) is a key regulator of the nucleus accumbens shell function in animals' responses to emotional stimuli. The present study demonstrates that passive stress in the form of social isolation induces anhedonia and depression-like symptoms that are mediated by CREB activity and neuronal excitability.

Abstract - | Full Text - CREB regulation of nucleus accumbens excitability mediates social isolation–induced behavioral deficits | PDF (640 KB) - CREB regulation of nucleus accumbens excitability mediates social isolation–induced behavioral deficits | Supplementary information

Precision and diversity in an odor map on the olfactory bulb - pp210 - 220

Edward R Soucy, Dinu F Albeanu, Antoniu L Fantana, Venkatesh N Murthy & Markus Meister

doi:10.1038/nn.2262

The primary sensory areas are generally thought to be mapped according to the organizational structure of the sensory input; retinotopic, somatotopic, cochleotopic and even coarse chemotopic maps have all been identified in the brain. Optical imaging of the olfactory bulb now reveals that there is no fine-scale chemotopic map in the rodent olfactory bulb.

Abstract - | Full Text - Precision and diversity in an odor map on the olfactory bulb | PDF (1,522 KB) - Precision and diversity in an odor map on the olfactory bulb | Supplementary information

See also: News and Views by Schoppa

Neural correlates of categorical perception in learned vocal communication - pp221 - 228

Jonathan F Prather, Stephen Nowicki, Rindy C Anderson, Susan Peters & Richard Mooney

doi:10.1038/nn.2246

The authors show that individual sensorimotor neurons in freely behaving swamp sparrows exhibit categorical responses to features of their songs. The neuronal response boundary predicts the categorical perceptual boundary that was measured in field studies of the same sparrow population, but not the perceptual boundary in populations that learn different song dialects.

Abstract - | Full Text - Neural correlates of categorical perception in learned vocal communication | PDF (695 KB) - Neural correlates of categorical perception in learned vocal communication | Supplementary information

Bi-stable neural state switches - pp229 - 234

André Berndt, Ofer Yizhar, Lisa A Gunaydin, Peter Hegemann & Karl Deisseroth

doi:10.1038/nn.2247

Transgenic expression of microbial channelrhodopsins in neurons allows direct light activation of ionic currents. Here, the authors describe a modified channelrhodopsin that remains open for seconds once it is activated by light and can be 'switched off' by a second light flash, thereby obviating the need for constant illumination during an experiment.

Abstract - | Full Text - Bi-stable neural state switches | PDF (1,594 KB) - Bi-stable neural state switches