The Journal of Neuroscience, November 9, 2005 • 25(45):i • i This Week in The Journal F Cellular/Molecular axons along distinct paths? This week, Liu and Halloran address that question in Snapin-Less Mice and Chromaffin Rohon-Beard (RB) sensory neurons in ze- Cell Exocytosis brafish embryos. Using live imaging, the authors report that central axons chugged Jin-Hua Tian, Zheng-Xing Wu, Michael along straight paths at a steady 20 ␮m/h. Unzicker, Li Lu, Qian Cai, Cuiling Li, Peripheral axons emerged from the cen- Claudia Schirra, Ulf Matti, David tral axon and exited the spinal cord, scat- Stevens, Chuxia Deng, Jens Rettig, and tering and branching often to form an epi- Zu-Hang Sheng dermal network covering the trunk. The authors injected antisense morpholinos to (see pages 10546–10555) knock down, or cDNAs to misexpress, The calcium-dependent exocytosis of syn- putative guidance molecules. Sema- Want to test your sense of body ownership? Try the somatic aptic vesicles requires assembly of the sol- phorin3D, normally expressed in the spi- rubber hand illusion. See the article by Ehrsson et al. for uble N-ethyl maleimide sensitive factor nal cord roof plate, repelled peripheral but details. adaptor protein receptor (SNARE) com- not central axons, suggesting it may guide plex, consisting of the vesicular mem- peripheral axons out of the spinal cord. brane-associated protein synaptobrevin, The RB-expressed Ig superfamily mole- degree that correlated with the strength of the plasma membrane-associated protein cule transient axonal glycoprotein-1, the illusion. however, was required for forward growth syntaxin, and synaptosomal-associated ࡗ Neurobiology of Disease protein 25 kDa (SNAP-25). Before re- of central axons but had no effect on pe- ripheral axons. lease, the calcium-sensing protein synap- A2A, mGlu5, and Parkinsonism totagmin also must bind SNAP-25. f Behavioral/Systems/Cognitive Anil Kachroo, Lianna R. Orlando, David Snapin, first identified as a SNAP-25- K. Grandy, Jiang-Fan Chen, Anne B. binding protein, enhances the association The Rubber-Hand Illusion Revisited Young, and Michael A. Schwarzschild of synaptotagmin with SNAP-25. This H. Henrik Ehrsson, Nicholas P. Holmes, week, Tian et al. examine the role of (see pages 10414–10419) snapin in the release of dense-core vesicles and Richard E. Passingham in chromaffin cells using snapin-deficient (see pages 10564–10572) Antagonists for the metabotropic gluta- mice. Heterozygous animals appeared mate receptor mGlu5 and the adenosine normal, but homozygotes did not survive In this week’s Journal, Ehrsson et al. tested receptor A2A have shown anti-parkin- past birth. Although the loss of snapin did the feeling of body ownership using the sonian effects in preclinical studies. These not affect formation of the SNARE com- somewhat creepy sensation associated receptors also assemble in heteromeric plex, it did reduce the association between with the rubber-hand illusion. In the au- complexes in the striatum, suggesting SNAP-25 and synaptotagmin. In chro- thors’ version of the illusion, blindfolded they might work in concert. This week, maffin cells lacking snapin, the fast exocy- participants were guided to touch a rub- Kachroo et al. treated mice with reserpine, totic burst of release was reduced by ber hand with their left index finger. Si- which depletes striatal dopamine, and ex- nearly one-half and was rescued by over- multaneously, the experimenter touched amined interactions between mGlu5 and expression of snapin. Snapin appears to subjects on their right hand, creating, af- A2A receptors. In normal and dopamine- stabilize the readily releasable pool of ter some seconds, the feeling in most sub- depleted mice, the mGlu5 antagonist primed vesicles. jects that they were touching their own 2-methyl-6-(phenylethynyl)-pyridine hand. The rubber hand, experimenter, (MPEP) induced locomotor activity that Œ Development/Plasticity/Repair and subjects all wore gloves to minimize was augmented by the A2A antagonist tactile differences. Temporal synchrony of KW-6002. The MPEP action was absent in Two Axon Branches, Two Targets, the sensory signals was key to the illusion. mice lacking mGlu5 receptors and, inter- Two Guidance Molecules As opposed to previous uses of the illu- estingly, also in mice lacking A2A recep- sion, these experiments did not include a tors, D2 dopamine receptors, or both. The Yan Liu and Mary C. Halloran visual component, showing that tactile behavior was similarly missing from mice (see pages 10556–10563) and proprioceptive sensations are suffi- in which A2A receptors were conditionally cient to fool the subject into ownership of knocked out in postnatal forebrain, thus Axons and dendrites often respond differ- the hand. Functional magnetic resonance excluding a developmental effect. The D1 entially to guidance factors in developing imaging revealed that the ventral premo- dopamine receptor agonist SKF 38393, their characteristic patterns and orienta- tor and intraparietal cortices and cerebel- however, increased motor behavior in all tions, but what about cells that send two lum were activated during the illusion to a genotypes. The Journal of Neuroscience November 9, 2005 • Volume 25 Number 45 www.jneurosci.org i This Week in The Journal Journal Club 10337 Not Every Graft Has What It Takes to Attract a Mossy Fiber Yevgenia Kozorovitskiy 10339 The Tuning Properties of Antennal Lobe Projection Neurons Jason Aungst and Marc Spehr Toolbox 10341 Brain Microarray: Finding Needles in Molecular Haystacks Nicole M. Lewandowski and Scott A. Small Cover picture: A computer-rendered right- hemisphere looking at a slant rivalry stimulus. The Symposia and Mini-Symposia image is rendered such that when viewed with anaglyphic filters (i.e., a red filter in front of the left 10347 Neural Circuitry Underlying Rule Use in Humans and Nonhuman Primates eye and a green filter in front of the right eye), Silvia A. Bunge, Jonathan D. Wallis, Amanda Parker, Marcel Brass, stereoscopic depth is perceived. See article by Eveline A. Crone, Eiji Hoshi, and Katsuyuki Sakai Brouwer et al. for details (pages 10403–10413). This 10351 Lateralization of the VertebrateBrain: Taking the Side of Model Systems cover image may also be viewed in 3-D at Marnie E. Halpern, Onur Gu¨ntu¨rku¨n, William D. Hopkins, and Lesley J. Rogers www.jneurosci.org/content/vol25/issue45 with anaglyphic glasses. For a set of anaglyphic glasses, 10358 Flashy Science: Controlling Neural Function with Light print subscribers may send a self-addressed, stamped Scott M. Thompson, Joseph P. Y. Kao, Richard H. Kramer, Kira E. Poskanzer, envelope to the Journal Central Office. Anaglyphic R. Angus Silver, David Digregorio, and Samuel S.-H. Wang glasses available while supplies last. 10366 New Neurons in the Adult Mammalian Brain: Synaptogenesis and Functional Integration Hongjun Song, Gerd Kempermann, Linda Overstreet Wadiche, Chunmei Zhao, Alejandro F. Schinder, and Josef Bischofberger 10369 Time and the Brain: How Subjective Time Relates to Neural Time David M. Eagleman, Peter U. Tse, Dean Buonomano, Peter Janssen, Anna Christina Nobre, and Alex O. Holcombe 10372 The Role of RNA and RNA Processing in Neurodegeneration Jean-Marc Gallo, Peng Jin, Charles A. Thornton, Hong Lin, Janice Robertson, Ian D’Souza, and William W. Schlaepfer 10376 Wnt Signaling in Neural Circuit Development Lee G. Fradkin, Gian Garriga, Patricia C. Salinas, John B. Thomas, Xiang Yu, and Yimin Zou 10379 Epigenetic Mechanisms and Gene Networks in the Nervous System Christine M. Colvis, Jonathan D. Pollock, Richard H. Goodman, Soren Impey, John Dunn, Gail Mandel, Frances A. Champagne, Mark Mayford, Edward Korzus, Arvind Kumar, William Renthal, David E. H. Theobald, and Eric J. Nestler 10390 Neurobiological Mechanisms of the Placebo Effect Fabrizio Benedetti, Helen S. Mayberg, Tor D. Wager, Christian S. Stohler, and Jon-Kar Zubieta Articles CELLULAR/MOLECULAR ⑀ 10462 Kinetics and Spontaneous Open Probability Conferred by the Subunit of the GABAA Receptor David A. Wagner, Marcel P. Goldschen-Ohm, Tim G. Hales, and Mathew V. Jones 10469 Gephyrin Regulates the Cell Surface Dynamics of Synaptic GABAA Receptors Tija C. Jacob, Yury D. Bogdanov, Christopher Magnus, Richard S. Saliba, Josef T. Kittler, Philip G. Haydon, and Stephen J. Moss 10479 Src-Family Kinases Stabilize the Neuromuscular Synapse In Vivo via Protein Interactions, Phosphorylation, and Cytoskeletal Linkage of Acetylcholine Receptors Gayathri Sadasivam, Raffaella Willmann, Shuo Lin, Susanne Erb-Vo¨gtli, Xian Chu Kong, Markus A. Ru¨egg, and Christian Fuhrer 10520 Metabotropic Glutamate Receptor 8-Expressing Nerve Terminals Target Subsets of GABAergic Neurons in the Hippocampus Francesco Ferraguti, Thomas Klausberger, Philip Cobden, Agnes Baude, J. David B. Roberts, Peter Szucs, Ayae Kinoshita, Ryuichi Shigemoto, Peter Somogyi, and Yannis Dalezios 10537 Dopamine Modulation of State-Dependent Endocannabinoid Release and Long-Term Depression in the Striatum Anatol C. Kreitzer and Robert C. Malenka ᭹ 10546 The Role of Snapin in Neurosecretion: Snapin Knock-Out Mice Exhibit Impaired Calcium-Dependent Exocytosis of Large Dense-Core Vesiclesin Chromaffin Cells Jin-Hua Tian, Zheng-Xing Wu, Michael Unzicker, Li Lu, Qian Cai, Cuiling Li, Claudia Schirra, Ulf Matti, David Stevens, Chuxia Deng, Jens Rettig, and Zu-Hang Sheng DEVELOPMENT/PLASTICITY/REPAIR 10437 Migration from a Mitogenic Niche Promotes Cell-Cycle Exit Yoojin Choi, Paul R. Borghesani, Jennifer A. Chan, and Rosalind A. Segal Œ 10556 Central