Journal of Computational Neuroscience This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

A modeling study of spinal motoneuron recruitment regulated by ionic channels during fictive locomotion
AbstractDuring fictive locomotion cat lumbar motoneurons exhibit changes in membrane proprieties including a decrease in voltage threshold (Vth), afterhyperpolarization (AHP) and input resistance (Rin) and an increase in non-linear membrane property. The impact of these changes on the motoneuron recruitment remains unknown. Using modeling approach we investigated the channel mechanism regulating the motoneuron recruitment. Three types of motoneuron pools including slow (S), fatigue-resistant (FR) and fast-fatigable (FF) motoneurons were constructed based on the membrane proprieties of cat lumbar motoneurons. The transient ...
Source: Journal of Computational Neuroscience - September 7, 2020 Category: Neuroscience Source Type: research

A computational investigation of electrotonic coupling between pyramidal cells in the cortex
AbstractThe existence of electrical communication among pyramidal cells (PCs) in the adult cortex has been debated by neuroscientists for several decades. Gap junctions (GJs) among cortical interneurons have been well documented experimentally and their functional roles have been proposed by both computational neuroscientists and experimentalists alike. Experimental evidence for similar junctions among pyramidal cells in the cortex, however, has remained elusive due to the apparent rarity of these couplings among neurons. In this work, we develop a neuronal network model that includes observed probabilities and strengths o...
Source: Journal of Computational Neuroscience - September 4, 2020 Category: Neuroscience Source Type: research

Computational analysis of a 9D model for a small DRG neuron
AbstractSmall dorsal root ganglion (DRG) neurons are primary nociceptors which are responsible for sensing pain. Elucidation of their dynamics is essential for understanding and controlling pain. To this end, we present a numerical bifurcation analysis of a small DRG neuron model in this paper. The model is of Hodgkin-Huxley type and has 9 state variables. It consists of a Nav1.7 and a Nav1.8 sodium channel, a leak channel, a delayed rectifier potassium, and an A-type transient potassium channel. The dynamics of this model strongly depend on the maximal conductances of the voltage-gated ion channels and the external curren...
Source: Journal of Computational Neuroscience - August 29, 2020 Category: Neuroscience Source Type: research

Spatiotemporal regulation of GABA concentration in extracellular space by gliotransmission crucial for extrasynaptic receptor-mediated improvement of sensory tuning performance in schizophrenia
AbstractIn schizophrenic patients, sensory tuning performance tends to be deteriorated (i.e., flattened sensory tuning), for which impaired intracortical tonic inhibition arising from a reduction in GABA concentration in extracellular space might be responsible. Theδ subunit-containing GABAA receptor, located on extrasynaptic sites, is known to be involved in mediating tonic inhibitory currents in cortical pyramidal cells and is considered to be one of the beneficial therapeutic targets for the treatment of schizophrenia. The transporter GAT-1 in glial (astrocytic) membrane controls concentration of GABA molecules by remo...
Source: Journal of Computational Neuroscience - July 31, 2020 Category: Neuroscience Source Type: research

Hot coffee: associative memory with bump attractor cell assemblies of spiking neurons
AbstractNetworks of spiking neurons can have persistently firing stable bump attractors to represent continuous spaces (like temperature). This can be done with a topology with local excitatory synapses and local surround inhibitory synapses. Activating large ranges in the attractor can lead to multiple bumps, that show repeller and attractor dynamics; however, these bumps can be merged by overcoming the repeller dynamics. A simple associative memory can include these bump attractors, allowing the use of continuous variables in these memories, and these associations can be learned by Hebbian rules. These simulations are re...
Source: Journal of Computational Neuroscience - July 26, 2020 Category: Neuroscience Source Type: research

Correction to: Psychophysical detection and learning in freely behaving rats: a probabilistic dynamical model for operant conditioning
The original version of this article unfortunately has some typographical errors in equations (5), (6), (7), (8), and (12). (Source: Journal of Computational Neuroscience)
Source: Journal of Computational Neuroscience - July 22, 2020 Category: Neuroscience Source Type: research

Lessons learned from the syndrome of oculopalatal tremor
AbstractThe syndrome of oculopalatal tremor (OPT) featuring the olivo-cerebellar hypersychrony leads to disabling pendular nystagmus and palatal myoclonus. This rare disorder provides valuable information about the motor physiology and offers insights into the mechanistic underpinning of common movement disorders. This focused review summarizes the last decade of OPT research from our laboratory and addresses three critical questions: 1) How the disease of inferior olive affects the physiology of motor learning? We discovered that our brain ’s ability to compensate for the impaired motor command and implement errors to c...
Source: Journal of Computational Neuroscience - July 17, 2020 Category: Neuroscience Source Type: research

Macaque monkeys show reversed ocular following responses to two-frame-motion stimulus presented with inter-stimulus intervals
AbstractWhen two-frame apparent motion stimuli are presented with an appropriate inter-stimulus interval (ISI), motion is perceived in the direction opposite to the actual image shift. Herein, we measured a simple eye movement, ocular following responses (OFRs), in macaque monkeys to examine the ISI reversal effect on oculomotor. Two-frame movies with an ISI induced reversed OFRs. Without ISI, the OFRs to the two-frame movie were induced in the direction of the stimulus shift. However, with ISIs ≥10 ms, OFRs in the direction opposite to the phase shift were observed. This directional reversal persisted for ISIs up to 16...
Source: Journal of Computational Neuroscience - July 16, 2020 Category: Neuroscience Source Type: research

Psychophysical detection and learning in freely behaving rats: a probabilistic dynamical model for operant conditioning
We present a stochastic learning model that combines the essential elements of Hebbian and Rescorla-Wagner theories for operant conditioning. The model was used to predict the behavioral data of rats performing a vibrotactile yes/no detection task. Probabilistic nature of learning was implemented by trial-by-trial variability in the random distributions of associative strengths between the sensory and the response representations. By using measures derived from log-likelihoods (corrected Akaike and Bayesian information criteria), the proposed model and its subtypes were compared with each other, and with previous models in...
Source: Journal of Computational Neuroscience - July 7, 2020 Category: Neuroscience Source Type: research

A computational approach for the inverse problem of neuronal conductances determination
AbstractThe derivation by Alan Hodgkin and Andrew Huxley of their famous neuronal conductance model relied on experimental data gathered using the squid giant axon. However, the experimental determination of conductances of neurons is difficult, in particular under the presence of spatial and temporal heterogeneities, and it is also reasonable to expect variations between species or even between different types of neurons of the same species.We tackle the inverse problem of determining, given voltage data, conductances with non-uniform distribution in the simpler setting of a passive cable equation, both in a single or bra...
Source: Journal of Computational Neuroscience - July 5, 2020 Category: Neuroscience Source Type: research

Optogenetic activation of corticogeniculate feedback stabilizes response gain and increases information coding in LGN neurons
AbstractIn spite of their anatomical robustness, it has been difficult to establish the functional role of corticogeniculate circuits connecting primary visual cortex with the lateral geniculate nucleus of the thalamus (LGN) in the feedback direction. Growing evidence suggests that corticogeniculate feedback does not directly shape the spatial receptive field properties of LGN neurons, but rather regulates the timing and precision of LGN responses and the information coding capacity of LGN neurons. We propose that corticogeniculate feedback specifically stabilizes the response gain of LGN neurons, thereby increasing their ...
Source: Journal of Computational Neuroscience - July 5, 2020 Category: Neuroscience Source Type: research

Gabapentin and memantine increases randomness of oscillatory waveform in ocular palatal tremor
AbstractSyndrome of oculopalatal tremor (OPT) causes pendular nystagmus of the eyes and its disabling consequence on the visual system. Classic pharmacotherapeutic studies revealed reduction in the eye velocity of the oscillatory waveforms. Subjective improvement in vision, however, remains out of proportionately low. Elegant models depicting quasi-sinusoidal coarse oscillations of the eyes highlighted two distinct oscillators; one at the inferior olive causing primary 2  Hz oscillations, while the second, independent oscillator, at the cerebellum adding the randomness to the waveform. Here we examined whether pharmacothe...
Source: Journal of Computational Neuroscience - July 2, 2020 Category: Neuroscience Source Type: research

Non-replicability circumstances in a neural network model with Hodgkin-Huxley-type neurons
In this study, we used a previously published code to investigate neural network activity and we were unable to replicate our original results. This led us to investigate the code in question, and we found that several different aspects, attributable to floating-point arithmetic, were the cause of these replicability issues. Furthermore, we uncovered other manifestations of this lack of replicability in other parts of the computation with this model. The simulated model is a standard system of ordinary differential equations, very much like those commonly used in computational neuroscience. Thus, we believe that other rese...
Source: Journal of Computational Neuroscience - June 8, 2020 Category: Neuroscience Source Type: research

3D human arm reaching movement planning with principal patterns in successive phases
In this study, we propose an algorithm in which, Arm Reaching Movement (ARM) in 3D space is decomposed into several successive phases using zero joint angle jerk features of the arm kinematic data. The presented decomposition algorithm for 3D motions is, in fact, an improved and generalized version of the decomposition method proposed earlier by Emadi and Bahrami in 2012 for 2D movements. They assumed that the motion is coordinated by minimum jerk characteristics in joint angles space in each phase. However, at the first glance, it seems that in 3D ARM joint angles are not coordinated based on the minimum jerk features. Th...
Source: Journal of Computational Neuroscience - May 25, 2020 Category: Neuroscience Source Type: research

Effects of Focal Axonal Swelling Level on the Action Potential Signal Transmission
This article discusses the results of a series of newly developed computational studies to elucidate the possible intervention or blockage of AP signals due to swelling in the brain. We argue that the spherical geometry of the swelling site with its enlarged conducting interior causes the entering electric currents to spread evenly over the entire swelled membrane. As such, when the swelled surface becomes larg er than the threshold size, the electric current will spread too thin to trigger the AP to spike. In this study, we have used a hybrid membrane model to simulate AP propagation across axons of different radii and sw...
Source: Journal of Computational Neuroscience - May 19, 2020 Category: Neuroscience Source Type: research