A Photon-Driven Micromotor Can Direct Nerve Fiber Growth Investigators have developed an optical-based system to control the direction of growth of individual axons using laser-driven spinning birefringent spheres. [Nat Photonics] Abstract Guanylate Binding Protein 1 Is a Novel Effector of EGFR-Driven Invasion in Glioblastoma In this study, researchers show that epidermal growth factor receptor (EGFR) activation promoted guanylate binding protein 1 expression in glioblastoma multiforme cell lines through a signaling pathway involving Src and p38 mitogen-activated protein kinase. [J Exp Med] Abstract | Press Release GABAergic Circuits Mediate the Reinforcement-Related Signals of Striatal Cholinergic Interneurons Here scientists describe the synaptic organization of a previously unknown circuit that involves direct nicotinic excitation of several classes of GABAergic interneurons, including neuroptide Y-expressing neurogilaform neurons, and enables cholinergic interneurons to exert rapid inhibitory control of the activity of projection neurons. [Nat Neurosci] Abstract Neuregulin 1 Represses Limbic Epileptogenesis through ErbB4 in Parvalbumin-Expressing Interneurons Using rodent models, here investigators show that limbic seizure activity upregulated neuregulin 1 (NRG1)-ErbB4 signaling and that epileptogenesis was inhibited by infusing NRG1 intracerebrally but exacerbated by neutralizing endogenous NRG1 with soluble ErbB4 extracellular domain, by inhibiting ErbB4 activation or by deleting the Erbb4 gene. [Nat Neurosci] Abstract Transient Receptor Potential A1 Channels Regulate Astrocyte Resting Calcium and Inhibitory Synapse Efficacy through GAT-3 Here, using a membrane-tethered, genetically encoded calcium indicator, researchers report the serendipitous discovery of a new type of Ca2+ signal in rat hippocampal astrocyte-neuron cocultures. [Nat Neurosci] Abstract Neuregulin 1 Regulates Excitability of Fast-Spiking Neurons through Kv1.1 and Acts in Epilepsy Researchers hypothesized that downregulation of neuregulin 1-ErbB4 signaling in fast-spiking, parvalbumin-positive interneurons is involved in epilepsy. [Nat Neurosci] Abstract A Critical Role for the PAR-1/MARK-tau Axis in Mediating the Toxic Effects of Aβ on Synapses and Dendritic Spines Using primary cultures of rat hippocampal neurons as a model system, investigators show that the PAR-1/MARK family kinases act as critical mediators of amyloid-β (Aβ) toxicity on synapses and dendritic spines. [Hum Mol Genet] Abstract Lack of a p21waf1/cip-Dependent G1/S Checkpoint in Neural Stem and Progenitor Cells After DNA Damage In Vivo Researchers employed staggered EdU/BrdU double-labeling in vivo to investigate the cell cycle progression and the role of p21waf1/cip in the DNA damage response of neural stem and progenitor cells after exposure of the developing mouse cortex to ionizing radiation. [Stem Cells] Abstract Epigenetic Enhancement of Brain-Derived Neurotrophic Factor Signaling Rescues Synaptic Plasticity in Aging Here investigators demonstrated age-dependent deficits in long-term synaptic plasticity and loss of dendritic spines in the hippocampus of aged Fisher 344 rats, which were closely associated with reduced histone acetylation, upregulation of histone deacetylase 2, and decreased expression of a histone acetyltransferase. [J Neurosci] Abstract | Press Release Efficient Conversion of Astrocytes to Functional Midbrain Dopaminergic Neurons Using a Single Polycistronic Vector Researchers report the reprogramming of astrocytes to dopaminergic neurons using three transcription factors – ASCL1, LMX1B, and NURR1 – delivered in a single polycistronic lentiviral vector. [PLoS One] Abstract | Press Release |