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J Darnell, KH2 domain I304N RGG G
J Darnell, KH2 domain I304N RGG G

... Sensory to L7 motor neuron “plastic” synapse Neuron need not be present for synaptogenesis Synaptogenesis is anisomycin sensitive 80-100 mRNAs transported to neuritic region Sensorin—Orphan peptide Expressed in sensory neuron, not in L7 Translational regulation, not dependent on transcription Specif ...
Building silicon nervous systems with dendritic tree neuromorphs
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... It is clear from a growing body of physiological work on neurons from many areas of the brain that dendritic membranes contain ionic channels that are voltage−dependent or influenced by intracellular second messenger systems [Hille, 1992]. Such mechanisms allow for non−linear operations, such as the ...
neural_networks
neural_networks

... quantitative aspect of the total pattern we associate with that individual. A feature can be an axis in a higher dimensional geometric space. Qualitative features can also be valued, as zero or one, for the absence or presence of a feature (e.g., ‘has a driver’s license’) We will only use non-negati ...
Pansynaptic Enlargement at Adult Cortical
Pansynaptic Enlargement at Adult Cortical

... enables the effects of either experience-dependent plasticity or perceptual learning (Guic-Robles et al. 1989; Harris et al. 1999) on the structure–function relationship at synapses to be studied in SI after altering whisker sensory input. Trimming a subset of the whiskers of mature rats for weeks r ...
NMDA Receptors Contribute to Primary Visceral Afferent
NMDA Receptors Contribute to Primary Visceral Afferent

... that very likely affect many NTS neurons. Thus although microinjection studies provide crucial data regarding the functional significance of non-NMDA and NMDA receptors on NTS neurons for full expression of various autonomic reflex responses, they cannot determine with certainty the extent to which ...
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An ultra small array of electrodes for stimulating multiple

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Short-Term Synaptic Plasticity Orchestrates the Response of Pyramidal

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Complex Cell-like Direction Selectivity through Spike

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... corresponding output patterns, Y1, Y2, and Y3. In these input and Left, a highly simplified model is used to illustrate how a synaptic output patterns 1 and 0 represent an action potential or no action matrix can store memory. In this synaptic matrix, axons of five potential, respectively. The integ ...
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... vesicle recycling kinetics in these animals. These results suggest that FXS is associated with abnormal STP and information processing in excitatory hippocampal synapses. Auditory nerve: converging synapses develop matched release probabilities A major issue concerning short-term plasticity is how i ...
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... Introduction: Gabapentin (GBP) is a novel analogue of GABA used widely in the treatment of epileptic partial seizures and neuropathic pain. GBP blocks Ca2+ channels in neural cell membrane and diminishes excitation of neurons. Such mechanism of action of this drug can predict GBP as a potential neur ...
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Chapter 12 *Lecture PowerPoint Nervous Tissue

... • About 1 trillion (1012) neurons in the nervous system • Neuroglia outnumber the neurons by as much as 50 to 1 • Neuroglia or glial cells – Support and protect the neurons – Bind neurons together and form framework for nervous tissue – In fetus, guide migrating neurons to their destination – If mat ...
A first-principle for the nervous system
A first-principle for the nervous system

... cue stimulus. The cue stimulus is expected to induce units of internal sensations that undergo a computational process at physiological time-scales. For example, rapidly changing a general cue stimulus step-by-step towards a specific one leads to corresponding changes in the retrieved memories from ...
Stochastic Model of Central Synapses: Slow Diffusion of Transmitter
Stochastic Model of Central Synapses: Slow Diffusion of Transmitter

... interactions with transporter molecules are assumed to affect the transmitter motion. We estimate the transporter density to be 5170 to 8900 mm − 2 in the synaptic cleft and its vicinity, using the experimentally observed time constant of glutamate. Furthermore a theoretical model of synaptic transm ...
Network Self-Organization Explains the Statistics and
Network Self-Organization Explains the Statistics and

... from self-organization induced by neuronal plasticity mechanisms, we have developed a self-organizing recurrent network (SORN) model. It extends a previous model [18], and consists of noisy binary threshold spiking neurons (80% excitatory and 20% inhibitory) and uses five different forms of plastici ...
Solving the Distal Reward Problem through
Solving the Distal Reward Problem through

... regular spiking type and 20% inhibitory neurons of the fast spiking type (Connors and Gutnick 1990), representing the layer 2/3 part of a cortical minicolumn. Neurons are randomly connected with 10% probability so that there are 100 synapses per averaged neuron. The connections, combined with the ra ...
2011 - Università degli studi di Pavia
2011 - Università degli studi di Pavia

... the granular layer and by detecting known patterns in Purkinje cells; (2) pattern recognition in Purkinje cells is regulated by memory storage at the parallel fiber–Purkinje cell synapse under climbing–fiber control; (3) when unfamiliar patterns are detected, the Purkinje cells change their firing r ...
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Long-term depression

Long-term depression (LTD), in neurophysiology, is an activity-dependent reduction in the efficacy of neuronal synapses lasting hours or longer following a long patterned stimulus. LTD occurs in many areas of the CNS with varying mechanisms depending upon brain region and developmental progress. LTD in the hippocampus and cerebellum have been the best characterized, but there are other brain areas in which mechanisms of LTD are understood. LTD has also been found to occur in different types of neurons that release various neurotransmitters, however, the most common neurotransmitter involved in LTD is L-glutamate. L-glutamate acts on the N-methyl-D- asparate receptors (NMDARs), α-amino-3-hydroxy-5-methylisoxazole-4-propionicacid receptors (AMPARs), kainate receptors (KARs) and metabotropic glutamate receptors (mGluRs) during LTD. It can result from strong synaptic stimulation (as occurs in the cerebellar Purkinje cells) or from persistent weak synaptic stimulation (as in the hippocampus). Long-term potentiation (LTP) is the opposing process to LTD; it is the long-lasting increase of synaptic strength. In conjunction, LTD and LTP are factors affecting neuronal synaptic plasticity. LTD is thought to result mainly from a decrease in postsynaptic receptor density, although a decrease in presynaptic neurotransmitter release may also play a role. Cerebellar LTD has been hypothesized to be important for motor learning. However, it is likely that other plasticity mechanisms play a role as well. Hippocampal LTD may be important for the clearing of old memory traces. Hippocampal/cortical LTD can be dependent on NMDA receptors, metabotropic glutamate receptors (mGluR), or endocannabinoids. The result of the underlying-LTD molecular mechanism is the phosphorylation of AMPA glutamate receptors and their elimination from the surface of the parallel fiber-Purkinje cell (PF-PC) synapse.LTD is one of several processes that serves to selectively weaken specific synapses in order to make constructive use of synaptic strengthening caused by LTP. This is necessary because, if allowed to continue increasing in strength, synapses would ultimately reach a ceiling level of efficiency, which would inhibit the encoding of new information.
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