The role of hippocampus to amygdala projection in two way active avoidance

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The roles of GluN2B containing silent synapses during cocaine exposure

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Silent synapse contribution to behavioral alterations after chronic cocaine exposure by D1-MSN specific GluN2B modulation

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NbO₂-Based Frequency Storable Coupled Oscillators for Associative Memory Application

Oscillatory neural networks with nano-oscillators and synapse devices are a promising alternative to implement neuromorphic systems owing to its fast recognition speed and low power consumption. In this paper, we demonstrate a compact frequency storable oscillator using nanoscale two-terminal NbO2 insulator-metal-transition devices along with TaOx-based resistive switching memory (RRAM) devices. By controlling RRAM resistance, we realized a wide range of analog oscillation frequencies. The synchronization window of two coupled oscillators, which is a key parameter for determining pattern recognition, increases with the increasing coupling capacitance and decreasing RRAM resistance of the reference oscillator. The simple device structure (metal-NbO2-metal-TaOx-metal), small device area (4F2), and frequency storability of NbO2-based coupled oscillator device show a strong potential for future integrated neuromorphic device application

The relation of functional states of dendritic spines with contents of micro-RNA

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Effect of conductance linearity and multi-level cell characteristics of TaOx-based synapse device on pattern recognition accuracy of neuromorphic system

To improve the classification accuracy of an image data set (CIFAR-10) by using analog input voltage, synapse devices with excellent conductance linearity (CL) and multi-level cell (MLC) characteristics are required. We analyze the CL and MLC characteristics of TaOx-based filamentary resistive random access memory (RRAM) to implement the synapse device in neural network hardware. Our findings show that the number of oxygen vacancies in the filament constriction region of the RRAM directly controls the CL and MLC characteristics. By adopting a Ta electrode (instead of Ti) and the hot-forming step, we could form a dense conductive filament. As a result, a wide range of conductance levels with CL is achieved and significantly improved image classification accuracy is confirmed.113sciescopu

Facile "stop codon" method reveals elevated neuronal toxicity by discrete S87p-alpha-synuclein oligomers

Herein, a new method for preparing phosphorylated proteins at specific sites has been applied to alpha-synuclein (alpha-Syn). Three different alpha-Syn species phosphorylated at Serine 87 (S87p-alpha-Syn), Serine 129 (S129p-alpha-Syn) and Serine 87/129 (S87p,129p-alpha-Syn) were prepared through the 'stop codon' method and verified by LC/MS/MS and immunoblotting. Each type of phosphorylated alpha-Syn was tested for oligomerization trends and cellular toxicity with dopamine (DA), Cu2+ ions and pyridoxal 5'-phosphate. Aggregation trends induced by DA or DA/Cu2+ were similar between phosphorylated and non-phosphorylated alpha-Syn in SDS-PAGE. However, except for the monomer, phosphorylated oligomers showed higher toxicity than the non-phosphorylated alpha-Syn (Np-alpha-Syn) oligomers via WST-1 assays when tested on SH-SY5Y human neuroblastoma cells. In particular, S87p-alpha-Syn and S87p,129p-alpha-Syn oligomers induced by DA/Cu2+, showed higher toxicity than did S129p-alpha-Syn. When alpha-Syn was treated with pyridoxal 5'-phosphate in the presence of DA or Cu2+ to determine aggregation effects, high inhibition effects were shown in both non-phosphorylated and phosphorylated versions. alpha-Syn co-incubated with DA or DA/Cu2+ showed less cellular toxicity upon pyridoxal 5'-phosphate treatment, especially in the case of DA-induced Np-alpha-Syn. This study supports that phosphorylated oligomers of alpha-Syn at residue 87 can contribute to neuronal toxicity and the pyridoxal 5'-phosphate can be used as an inhibitor for alpha-Syn aggregation. (C) 2013 Elsevier Inc. All rights reserved.N

Dynamical prefrontal population coding during defensive behaviours

Coping with threatening situations requires both identifying stimuli that predict danger and selecting adaptive behavioural responses to survive1. The dorsomedial prefrontal cortex (dmPFC) is a critical structure that is involved in the regulation of threat-related behaviour2,3,4. However, it is unclear how threat-predicting stimuli and defensive behaviours are associated within prefrontal networks to successfully drive adaptive responses. Here we used a combination of extracellular recordings, neuronal decoding approaches, pharmacological and optogenetic manipulations to show that, in mice, threat representations and the initiation of avoidance behaviour are dynamically encoded in the overall population activity of dmPFC neurons. Our data indicate that although dmPFC population activity at stimulus onset encodes sustained threat representations driven by the amygdala, it does not predict action outcome. By contrast, transient dmPFC population activity before the initiation of action reliably predicts avoided from non-avoided trials. Accordingly, optogenetic inhibition of prefrontal activity constrained the selection of adaptive defensive responses in a time-dependent manner. These results reveal that the adaptive selection of defensive responses relies on a dynamic process of information linking threats with defensive actions, unfolding within prefrontal networks.Rôle de la signalisation dopaminergique dans l'amygdale étendue dans le contrôle de la peur généralisée.Role des projections inhibitrices provenant du cortex préfrontal dans l'expression de la peur conditionnéeInnovations instrumentales et procédurales en psychopathologie expérimentale chez le rongeu