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Artikel Jurnal
Information carried by population spike times in the whisker sensory cortex can be decoded without knowledge of stimulus time
Computational analyses have revealed that precisely timed spikes emitted by somatosensory cortical neuronal populations encode basic stimulus features in the rat’s whisker sensory system. Efficient spike time based decoding schemes both for the spatial location of a stimulus and for the kinetic…
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Artikel Jurnal
Taking a back seat: synaptic vesicle clustering in presynaptic terminals
Central inter-neuronal synapses employ various molecular mechanisms to sustain neurotransmitter release during phases of high-frequency synaptic activity. One of the features ensuring this property is the presence of a pool of synaptic vesicles (SVs) in the presynaptic terminal. At rest and low…
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Artikel Jurnal
STDP and mental retardation: dysregulation of dendritic excitability in Fragile X syndrome
Development of cognitive function requires the formation and refinement of synaptic networks of neurons in the brain. Morphological abnormalities of synaptic spines occur throughout the brain in a wide variety of syndromic and non-syndromic disorders of mental retardation (MR). In both neurons from…
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Transcranial magnetic stimulation provides means to assess cortical plasticity and excitability in humans with fragile X syndrome and autism spectrum disorder
Fragile X Syndrome (FXS) is the most common heritable cause of intellectual disability. In vitro electrophysiologic data from mouse models of FXS suggest that loss of Fragile X Mental Retardation Protein (FMRP) affects intracortical excitability and synaptic plasticity. Specifically, the cortex…
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Artikel Jurnal
Synaptic vesicle pools: an update
During the last few decades synaptic vesicles have been assigned to a variety of functional and morphological classes or pools. We have argued in the past (Rizzoli SO and Betz WJ, 2005, Synaptic vesicle pools, Nat. Rev. Neurosci. 6, 57-69) that synaptic activity in several preparations is accounted…
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Artikel Jurnal
Voltage and spike timing interact in STDP - a unified model
A phenomenological model of synaptic plasticity is able to account for a large body of experimental data on Spike-Timing Dependent Plasticity. The basic ingredient of the model is the correlation of presynaptic spike arrival with postsynaptic voltage. The local membrane voltage is used twice: a…
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Artikel Jurnal
What is Rate-Limiting During Sustained Synaptic Activity: Vesicle Supply or the Availability of Release Sites
For some types of synapses the availability of release-ready vesicles is a limiting factor during ongoing activity. Synaptic strength in this case is determined both by the recruitment of such vesicles and the probability of their release during an action potential. Here it is argued that not the…
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Artikel Jurnal
Homeostatic plasticity and STDP: keeping a neuron's cool in a fluctuating world
Spike-timing dependent plasticity (STDP) offers a powerful means of forming and modifying neural circuits. Experimental and theoretical studies have demonstrated its potential usefulness for functions as varied as cortical map development, sharpening of sensory receptive fields, working memory, and…
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Artikel Jurnal
A re-examination of Hebbian-covariance rules and spike timing-dependent plasticity in cat visual cortex in vivo
Spike-Timing-Dependent Plasticity (STDP) is considered as an ubiquitous rule for associative plasticity in cortical networks in vitro. However, limited supporting evidence for its functional role has been provided in vivo. In particular, there are very few studies demonstrating the co-occurence of…
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Cortico-striatal spike-timing dependent plasticity after activation of subcortical pathways
Cortico-striatal spike-timing dependent plasticity (STDP) is modulated by dopamine in vitro. The present study investigated STDP in vivo using alternative procedures for modulating dopaminergic inputs. Postsynaptic potentials (PSP) were evoked in intracellularly recorded spiny neurons by electrical…
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Artikel Jurnal
The applicability of spike time dependent plasticity to development
Spike time dependent plasticity (STDP) has been observed in both developing and adult animals. Theoretical studies suggest that it implicitly leads to both competition and homeostasis in addition to correlation-based plasticity, making it a good candidate to explain developmental refinement and…
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Artikel Jurnal
Presynaptic NMDA receptors and spike timing-dependent long-term depression at cortical synapses
It has recently been discovered that some forms of timing-dependent long-term depression (t-LTD) require presynaptic N-methyl-D-aspartate (NMDA) receptors. In this review, we discuss the evidence for the presence of presynaptic NMDA receptors at cortical synapses and their possible role in the…
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Artikel Jurnal
Spike-timing dependent plasticity in the striatum
The striatum is the major input nucleus of basal ganglia, an ensemble of interconnected sub-cortical nuclei associated with fundamental processes of action-selection and procedural learning and memory. The striatum receives afferents from the cerebral cortex and the thalamus. In turn, it relays the…
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Artikel Jurnal
Spike-timing dependent plasticity in inhibitory circuits
Inhibitory circuits in the brain rely on GABA-releasing interneurons. For long, inhibitory circuits were considered weakly plastic in the face of patterns of neuronal activity that trigger long-term changes in the synapses between excitatory principal cells. Recent studies however have shown that…
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Artikel Jurnal
Plasticity resembling spike-timing dependent synaptic plasticity: the evidence in human cortex
Spike-timing dependent plasticity (STDP) has been studied extensively in a variety of animal models during the past decade but whether it can be studied at the systems level of the human cortex has been a matter of debate. Only recently newly developed non-invasive brain stimulation techniques such…
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Artikel Jurnal
Synaptic determinants of Rett syndrome
There is mounting evidence showing that the structural and molecular organization of synaptic connections are affected both in human patients and in animal models of neurological and psychiatric diseases. As a consequence of these experimental observations, it has been introduced the concept of…
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Chronic stress effects on hippocampal structure and synaptic function: relevance for depression and normalization by anti-glucocorticoid treatment
Exposure of an organism to environmental challenges activates two hormonal systems that help the organism to adapt. As part of this adaptational process, brain processes are changed such that appropriate behavioral strategies are selected that allow optimal performance at the short term, while…
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Artikel Jurnal
Summing across different active zones can explain the quasi-linear Ca2+-dependencies of exocytosis by receptor cells
Several recent studies of mature auditory and vestibular hair cells, and of visual and olfactory receptor cells, have observed nearly linear dependencies of the rate of neurotransmitter release events, or related measures, on the magnitude of Ca2+-entry into the cell. These relationships contrast…