Synaptic behavior and STDP of asymmetric nanoscale memristors in biohybrid systems.

02:34 EDT 2nd August 2014 | BioPortfolio

Summary of "Synaptic behavior and STDP of asymmetric nanoscale memristors in biohybrid systems."

We fabricate and characterize asymmetric memristors which show a very strong single-sided hysteresis. When biased in one direction there is hysteresis and in the opposite direction there is a lack of hysteresis. We demonstrate that this apparent lack is actually hysteresis on a much faster time-scale. We further demonstrate that this form of asymmetric behavior correlates very well to the asymmetric structure and function of an actual synapse. The asymmetric memristor device presented here is necessary to correctly implement spike-timing-dependent-plasticity STDP in mixed memristor/neuron hybrid systems as an artificial synapse. These devices show the required characteristics for implementing the asymmetric form of long-term potentiation (LTP) and long-term depression (LTD) of a synapse between two neurons, where symmetric memristor devices do not. Signals from a presynaptic neuron are sent via its axon across the synapse to the dendrite of a postsynaptic neuron. Postsynaptic neuron signals sent to subsequent neurons have an influence on the strength of any further presynaptic neuron signals received by the postsynaptic neuron across the synapse. These signals are grouped into spike triplets within the framework of STDP and, as we experimentally show here, can be implemented with asymmetric memristors, not standard symmetric memristors.

Affiliation

Department of Nano-Biosystem Technology, Technische Universität Ilmenau, Germany. adam.williamson@tu-ilmenau.de.

Journal Details

This article was published in the following journal.

Name: Nanoscale
ISSN: 2040-3372
Pages:

Links

PubMed Articles [12423 Associated PubMed Articles listed on BioPortfolio]

Shaping Synaptic Learning by the Duration of Postsynaptic Action Potential in a New STDP Model.

Single spikes and their timing matter in changing synaptic efficacy, which is known as spike-timing-dependent plasticity (STDP). Most previous studies treated spikes as all-or-none events, and conside...

The Effect of STDP Temporal Kernel Structure on the Learning Dynamics of Single Excitatory and Inhibitory Synapses.

Spike-Timing Dependent Plasticity (STDP) is characterized by a wide range of temporal kernels. However, much of the theoretical work has focused on a specific kernel - the "temporally asymmetric Hebbi...

Neuronal Synapse as a Memristor: Modeling Pair- and Triplet-Based STDP Rule.

We propose a new memristive model for the neuronal synapse based on the spike-timing-dependent plasticity (STDP) protocol, considering both long-term and short-term plasticity in the synapse. Higher-o...

Network Evolution Induced by Asynchronous Stimuli through Spike-Timing-Dependent Plasticity.

In sensory neural system, external asynchronous stimuli play an important role in perceptual learning, associative memory and map development. However, the organization of structure and dynamics of ne...

Systems Biology of Synaptic Plasticity: A Review on N-methyl-D-aspartate Receptor mediated Biochemical Pathways and related Mathematical Models.

Synaptic plasticity, an emergent property of synaptic networks, has shown strong correlation to one of the essential functions of the brain, memory formation. Through understanding synaptic plasticity...

Clinical Trials [1117 Associated Clinical Trials listed on BioPortfolio]

Effects of CX516 on Functioning in Fragile X Syndrome and Autism

This study will investigate whether CX516 can improve attention, memory, language, or behavior in adults with Fragile X Syndrome and/or Autism. CX516 is an AMPAKINE® compound. AMPAKINE...

Effect of Homocysteine and Asymmetric Dimethylarginine on Cardiovascular Events in Hemodialysis Patients

Homocysteine (Hcy) and asymmetric dimethylarginine (ADMA) have recently been recognized as potential risk factors for atherosclerosis in the general population, and the metabolism of each...

The Influence of Low Frequency Repetitive Transcranial Stimulation (r-TMS) on Motor and Cognitive Measurements in Patients With Asymmetric Parkinson's Disease

To test the effects of low frequency deep rTMS using the novel H-coil on the motor, affective and cognitive deficits in patients with asymmetric Parkinson's disease (PD) and to establish i...

Tetrabenazine for Partial Responders

Purpose of Study: A) To improve outcome in large population of antipsychotic patients with schizophrenia or schizoaffective who are only partial responders B) To increase understanding of...

Neonatal Pain- and Distress Experiences and Later Pain Behavior of Former Preterm and Critically Ill Newborn Infants

Preterm and critically ill neonates experience many painful manipulations. The aim of the study is to evaluate the influence of these experiences and maternal deprivation on later pain beh...

Medical and Biotech [MESH] Definitions

The communication from a NEURON to a target (neuron, muscle, or secretory cell) across a SYNAPSE. In chemical synaptic transmission, the presynaptic neuron releases a NEUROTRANSMITTER that diffuses across the synaptic cleft and binds to specific synaptic receptors, activating them. The activated receptors modulate specific ion channels and/or second-messenger systems in the postsynaptic cell. In electrical synaptic transmission, electrical signals are communicated as an ionic current flow across ELECTRICAL SYNAPSES.

Cell-surface proteins that bind glutamate and trigger changes which influence the behavior of cells. Glutamate receptors include ionotropic receptors (AMPA, kainate, and N-methyl-D-aspartate receptors), which directly control ion channels, and metabotropic receptors which act through second messenger systems. Glutamate receptors are the most common mediators of fast excitatory synaptic transmission in the central nervous system. They have also been implicated in the mechanisms of memory and of many diseases.

Nanometer-sized particles that are nanoscale in three dimensions. They include nanocrystaline materials; NANOCAPSULES; METAL NANOPARTICLES; DENDRIMERS, and QUANTUM DOTS. The uses of nanoparticles include DRUG DELIVERY SYSTEMS and cancer targeting and imaging.

The voltages across pre- or post-SYNAPTIC MEMBRANES.

The study of systems which respond disproportionately (nonlinearly) to initial conditions or perturbing stimuli. Nonlinear systems may exhibit "chaos" which is classically characterized as sensitive dependence on initial conditions. Chaotic systems, while distinguished from more ordered periodic systems, are not random. When their behavior over time is appropriately displayed (in "phase space"), constraints are evident which are described by "strange attractors". Phase space representations of chaotic systems, or strange attractors, usually reveal fractal (FRACTALS) self-similarity across time scales. Natural, including biological, systems often display nonlinear dynamics and chaos.

Search BioPortfolio:
Advertisement
Advertisement

Searches Linking to this Article