neural_networks
... i.e. assume that successive input sets, and the postsynaptic decisions they drive, occur in discrete, sequential time intervals (an input set contains one or more input patterns). Postsynaptic neuron makes a decision at each time interval based solely on its current input weights, its active inputs, ...
... i.e. assume that successive input sets, and the postsynaptic decisions they drive, occur in discrete, sequential time intervals (an input set contains one or more input patterns). Postsynaptic neuron makes a decision at each time interval based solely on its current input weights, its active inputs, ...
Rearrangement of microtubule polarity orientation during conversion
... [Burack et al., 2000; Setou et al., 2003]. It is thus important to understand the mechanisms that underlie the establishment and maintenance of microtubule polarity orientation in neuronal processes in order to understand those responsible for the establishment and maintenance of neuronal polarity i ...
... [Burack et al., 2000; Setou et al., 2003]. It is thus important to understand the mechanisms that underlie the establishment and maintenance of microtubule polarity orientation in neuronal processes in order to understand those responsible for the establishment and maintenance of neuronal polarity i ...
Efficient Recruitment of Layer 2/3 Interneurons by Layer 4 Input in
... from the pair shown in Figure 1. B, EPSP unitary amplitude histogram for this connection. White, noise; gray, sweeps including failures. C, AP-to-EPSP onset latency histogram. Note the narrow distribution (Gaussian fit with full width at half-maximum of 0.2 ms). D, Relationship between EPSP amplitud ...
... from the pair shown in Figure 1. B, EPSP unitary amplitude histogram for this connection. White, noise; gray, sweeps including failures. C, AP-to-EPSP onset latency histogram. Note the narrow distribution (Gaussian fit with full width at half-maximum of 0.2 ms). D, Relationship between EPSP amplitud ...
Columnar Organization of Dendrites and Axons of Single and
... boutons per unit axonal length was also highest there. Electron microscopy combined with GABA postimmunogold labeling revealed that most (⬎90%) of the synaptic contacts were established on dendritic spines and shafts of excitatory neurons in layers 4 and 2/3. The largely columnar organization of den ...
... boutons per unit axonal length was also highest there. Electron microscopy combined with GABA postimmunogold labeling revealed that most (⬎90%) of the synaptic contacts were established on dendritic spines and shafts of excitatory neurons in layers 4 and 2/3. The largely columnar organization of den ...
morphology and synaptic connections of ultrafine primary axons
... caliber as their ending-bearing segments in lamina I, i.e., -0.3 to 0.5 pm in diameter, which corresponds to the diameters of most of the unmyelinated axons that have been seen in electron micrographs of Lissauer’s tract (K. Chung et al., 1979; Gobel and Falls, 1979). The preterminal segments in Lis ...
... caliber as their ending-bearing segments in lamina I, i.e., -0.3 to 0.5 pm in diameter, which corresponds to the diameters of most of the unmyelinated axons that have been seen in electron micrographs of Lissauer’s tract (K. Chung et al., 1979; Gobel and Falls, 1979). The preterminal segments in Lis ...
Structure and Function in the Inferior Olivary Nucleus
... The inferior olivary nucleus is the source of the climbing fibres, one of the two major afferent pathways into the cerebellum. This thesis is concerned with aspects of the cellular anat ...
... The inferior olivary nucleus is the source of the climbing fibres, one of the two major afferent pathways into the cerebellum. This thesis is concerned with aspects of the cellular anat ...
Three-dimensional organization of dendrites and local axon
... reconstructions, cell bodies, axonal and/or dendritic arborizations, boundaries of the Acb shell/core and, in relevant cases, a patch compartment were precisely drawn under 25–639 oil immersion objectives. Furthermore, 3D models of these neurons were visualized using the Lightwave software (Newtek I ...
... reconstructions, cell bodies, axonal and/or dendritic arborizations, boundaries of the Acb shell/core and, in relevant cases, a patch compartment were precisely drawn under 25–639 oil immersion objectives. Furthermore, 3D models of these neurons were visualized using the Lightwave software (Newtek I ...
Solving the Distal Reward Problem through
... as the ‘‘distal reward problem’’ (Hull 1943) and in the reinforcement learning literature as the ‘‘credit assignment problem’’ (Minsky 1963; Barto et al. 1983; Houk, Adams, Barto 1995; Sutton and Barto 1998; Dayan and Abbott 2001; Worgotter and Porr 2005). Indeed, how does the animal know which of t ...
... as the ‘‘distal reward problem’’ (Hull 1943) and in the reinforcement learning literature as the ‘‘credit assignment problem’’ (Minsky 1963; Barto et al. 1983; Houk, Adams, Barto 1995; Sutton and Barto 1998; Dayan and Abbott 2001; Worgotter and Porr 2005). Indeed, how does the animal know which of t ...
Synaptic Pruning in Development: A Novel Account in Neural Terms
... in some species, the peak level of synaptic density is obtained at a very early age after birth (e.g. 2 weeks for the macaque monkeys [Bourgeois, 1993]). The changes in synaptic density are not a result of changes in total brain volume, but re ect true synaptic elimination [Rakic et al., 1994]. In s ...
... in some species, the peak level of synaptic density is obtained at a very early age after birth (e.g. 2 weeks for the macaque monkeys [Bourgeois, 1993]). The changes in synaptic density are not a result of changes in total brain volume, but re ect true synaptic elimination [Rakic et al., 1994]. In s ...
The Neurons of the Medial Geniculate Body in the Mustached Bat
... The neurons in the medial geniculate body were studied in Golgi preparations from adult mustached bats (Pteronotus parnellii). Their somatic and dendritic configurations were compared with those of cells in other, nonecholocating mammals. A second goal was to use the thalamic nuclear subdivisions de ...
... The neurons in the medial geniculate body were studied in Golgi preparations from adult mustached bats (Pteronotus parnellii). Their somatic and dendritic configurations were compared with those of cells in other, nonecholocating mammals. A second goal was to use the thalamic nuclear subdivisions de ...
A dendritic disinhibitory circuit mechanism for pathway
... with a reduced morphology (Fig. 2a; Supplementary Fig. 1). It comprises one spiking somatic compartment and multiple dendritic compartments, which are electrically coupled to the soma but otherwise independent of each other. The somatic and dendritic compartments have no spatial extent themselves. T ...
... with a reduced morphology (Fig. 2a; Supplementary Fig. 1). It comprises one spiking somatic compartment and multiple dendritic compartments, which are electrically coupled to the soma but otherwise independent of each other. The somatic and dendritic compartments have no spatial extent themselves. T ...
- White Rose Research Online
... 97% of the cell population in rat, with GABAergic and cholinergic interneurons forming most of the remaining cell population. Despite their comparatively small number, the GABAergic fastspiking interneurons (FSIs) in particular exert a very strong influence on the MSNs [20–22], receive input from si ...
... 97% of the cell population in rat, with GABAergic and cholinergic interneurons forming most of the remaining cell population. Despite their comparatively small number, the GABAergic fastspiking interneurons (FSIs) in particular exert a very strong influence on the MSNs [20–22], receive input from si ...
PDF file - Izhikevich
... (Braitenberg and Schuz, 1991). The ratio of excitatory to inhibitory neurons was 4/1. The span of local non-myelinated axonal collaterals of an excitatory neuron was 1.5 mm, and of an inhibitory neuron was 0.5 mm. The probability of synaptic connection between two nearby excitatory neurons was 0.09. ...
... (Braitenberg and Schuz, 1991). The ratio of excitatory to inhibitory neurons was 4/1. The span of local non-myelinated axonal collaterals of an excitatory neuron was 1.5 mm, and of an inhibitory neuron was 0.5 mm. The probability of synaptic connection between two nearby excitatory neurons was 0.09. ...
How Do Short-Term Changes at Synapses Fine
... during natural spike trains recorded in hippocampal place cells in behaving rodents. Time-dependent information analysis further predicted that this optimization of information transfer for spike bursts depends on the presence of facilitation/augmentation and is not present in high-release probabili ...
... during natural spike trains recorded in hippocampal place cells in behaving rodents. Time-dependent information analysis further predicted that this optimization of information transfer for spike bursts depends on the presence of facilitation/augmentation and is not present in high-release probabili ...
Neuronal morphology in the African elephant (Loxodonta africana
... focus on superficial (i.e., layers II–III) pyramidal neurons (mean soma depth = 794 ± 131 lm) in the two cortical regions. Because the Golgi impregnation was not uniform, more neurons appropriate for quantification were sampled from LA1 (n = 46) than from LA3 (n = 29). A total of 40 superficial pyra ...
... focus on superficial (i.e., layers II–III) pyramidal neurons (mean soma depth = 794 ± 131 lm) in the two cortical regions. Because the Golgi impregnation was not uniform, more neurons appropriate for quantification were sampled from LA1 (n = 46) than from LA3 (n = 29). A total of 40 superficial pyra ...
Review. Multiple signaling modalities mediated by dendritic
... communication is largely determined by the spatially constrained structure of the synapse. Conversely, in paracrine transmission, specificity is solely determined by the specificity of the signal – receptor interaction. Examples of signalling mechanisms acting at more distant sites include release o ...
... communication is largely determined by the spatially constrained structure of the synapse. Conversely, in paracrine transmission, specificity is solely determined by the specificity of the signal – receptor interaction. Examples of signalling mechanisms acting at more distant sites include release o ...
Multiple signalling modalities mediated by dendritic exocytosis of
... communication is largely determined by the spatially constrained structure of the synapse. Conversely, in paracrine transmission, specificity is solely determined by the specificity of the signal – receptor interaction. Examples of signalling mechanisms acting at more distant sites include release o ...
... communication is largely determined by the spatially constrained structure of the synapse. Conversely, in paracrine transmission, specificity is solely determined by the specificity of the signal – receptor interaction. Examples of signalling mechanisms acting at more distant sites include release o ...
The Dialectics of Hebb and Homeostasis within
... detected and summed over time to trigger Hebbian plasticity in vivo. Nonetheless, it seems likely that under some learning conditions Hebbian changes can happen quickly, so that the speed of homeostatic mechanisms becomes an important concern if they are assigned the task of preventing runaway poten ...
... detected and summed over time to trigger Hebbian plasticity in vivo. Nonetheless, it seems likely that under some learning conditions Hebbian changes can happen quickly, so that the speed of homeostatic mechanisms becomes an important concern if they are assigned the task of preventing runaway poten ...
Sleep Spindles as Facilitators of Memory Formation and Learning
... particularly at the transition to REM sleep were shown to be involved in the consolidation of novel memories [23]. These studies show that spindles play a role in learning also in other species and that laboratory animals can be used to investigate the underlying mechanisms (see below). The correlat ...
... particularly at the transition to REM sleep were shown to be involved in the consolidation of novel memories [23]. These studies show that spindles play a role in learning also in other species and that laboratory animals can be used to investigate the underlying mechanisms (see below). The correlat ...
Efficient Event-Driven Simulation of Large Networks of Spiking
... and consequently start drifting away from what was considered spontaneous rates or a computationally relevant distribution. The question of the stability, for any computational paradigm, must be considered central, in the sense that both the selectivity of the computational outcome and its separabil ...
... and consequently start drifting away from what was considered spontaneous rates or a computationally relevant distribution. The question of the stability, for any computational paradigm, must be considered central, in the sense that both the selectivity of the computational outcome and its separabil ...
Age-dependent effect of cholinergic lesion on dendritic morphology
... 1. Introduction Plasticity has long been known to be a property of developing nervous systems. Although originally considered to be a developmental phenomenon, plasticity extends into adulthood as well, underlying a variety of processes, including learning and memory as well as recovery from injury. ...
... 1. Introduction Plasticity has long been known to be a property of developing nervous systems. Although originally considered to be a developmental phenomenon, plasticity extends into adulthood as well, underlying a variety of processes, including learning and memory as well as recovery from injury. ...
166 - UCSF Physiology - University of California, San Francisco
... neurons in the developing cerebral cortex or hippocampus (suptrol animals, the cortex is normally organized into distinct layers plemental Fig. 1, available at www.jneurosci.org as supplemental with the cell-sparse layer I positioned closest to the pial surface material). Western blot analysis furth ...
... neurons in the developing cerebral cortex or hippocampus (suptrol animals, the cortex is normally organized into distinct layers plemental Fig. 1, available at www.jneurosci.org as supplemental with the cell-sparse layer I positioned closest to the pial surface material). Western blot analysis furth ...
Memory Maintenance in Synapses with Calcium
... Most models of learning and memory assume that memories are maintained in neuronal circuits by persistent synaptic modifications induced by specific patterns of pre- and postsynaptic activity. For this scenario to be viable, synaptic modifications must survive the ubiquitous ongoing activity present ...
... Most models of learning and memory assume that memories are maintained in neuronal circuits by persistent synaptic modifications induced by specific patterns of pre- and postsynaptic activity. For this scenario to be viable, synaptic modifications must survive the ubiquitous ongoing activity present ...
Simulation of signal flow in 3D reconstructions of an anatomically
... At present, observations of neuronal ensemble activity in the cortex, by optical or multi-electrode techniques, are limited. An alternative, reverse engineering approach is to reconstruct anatomically realistic neural circuits, to populate these circuits with measured spike activities and finally, t ...
... At present, observations of neuronal ensemble activity in the cortex, by optical or multi-electrode techniques, are limited. An alternative, reverse engineering approach is to reconstruct anatomically realistic neural circuits, to populate these circuits with measured spike activities and finally, t ...
Spike-Timing Theory of Working Memory
... Short-term amplification of synaptic responses via simulated NMDA receptors resulting in NMDA spikes. (B) Schematic diagram showing a multi-compartmental neuron (post) receiving a synapse from a presynaptic neuron (pre). (C) A train of presynaptic spikes is followed by a postsynaptic response delaye ...
... Short-term amplification of synaptic responses via simulated NMDA receptors resulting in NMDA spikes. (B) Schematic diagram showing a multi-compartmental neuron (post) receiving a synapse from a presynaptic neuron (pre). (C) A train of presynaptic spikes is followed by a postsynaptic response delaye ...
Dendritic spine
A dendritic spine (or spine) is a small membranous protrusion from a neuron's dendrite that typically receives input from a single synapse of an axon. Dendritic spines serve as a storage site for synaptic strength and help transmit electrical signals to the neuron's cell body. Most spines have a bulbous head (the spine head), and a thin neck that connects the head of the spine to the shaft of the dendrite. The dendrites of a single neuron can contain hundreds to thousands of spines. In addition to spines providing an anatomical substrate for memory storage and synaptic transmission, they may also serve to increase the number of possible contacts between neurons.