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This study presents a new approach to develop a model based seizure prediction system. In this system, a neural mass model is used to simulate the macro-scale dynamics of a cortical micro-zone and the local field potentials (LFP) generated by its activity. The LFP is modeling with an acceptable approximation of the intracranial EEG (iEEG) data. The model includes one population of pyramidal cells,...
In this paper we report the preliminary results of recognition of learned subjects from unlearned ones during foot writing process using electromyogram (EMG) signals recorded from thigh and shank muscles. For proof of idea, three subjects were asked to write seven letters with foot. We recorded and analyzed the data to study the learning process in five sessions. Since previous studies have shown...
Previous studies suggested that increasing speed has an effect on human walking features such as joints and muscles range of motion, related spatio-temporal parameters and muscles activation patterns. However, such an effect on more complicated indices e.g. muscle synergies, minimum angular jerk and cross correlation between different types of biomechanical gait data has not been studied in large...
Astrocytes, most numerous glial cells in brain, respond to neural activities by provoking calcium waves and releasing transmitters to adjacent synapses and consequently, modulate neural activities. Here, we used leaky integrate and fire (LIF) neuron and a minimal functional astrocyte models with detailed synaptic mechanism to investigate astrocyte modulation impact on firing of tripartite synapse...
In this preliminary study we aim to extract muscle synergies in spiral tracking task when performed with the non-dominant hand, and investigate the effect of training on muscle synergies. Three young subjects who were university students (all Females, 21±1 years old, right-handed) volunteered to participate in this study. The subjects were healthy with no history of neuromuscular disease. Each subject...
In this pilot study we investigated the effects of external and internal focus of attention on motor learning and performance during learning a balance control task. Pilot experiments were conducted by instructing two groups of healthy students (right footed). In the external-focus condition, performers were conducted to focus on a marker on the wall in front of them whereas in the internal focus...
The central nervous system (CNS) uses an abundant set of joints and muscles to ensure both flexible and stable movements. How the CNS faces the complexity of control problem is not still clear. Modular control is one of the most attractive hypotheses in motor control. In this hypothesis, some motor primitives are considered as the building blocks that can be combined to present a vast repertoire of...
Post-stroke patients usually suffer from lower and upper limbs disorders, which require intense rehabilitation therapies, among which hand function restoration is of a higher significance. This paper introduces the procedure of designing and modeling a novel finger-exoskeleton module (for each finger) in interaction with patients’ hand. In this study, our aim is to develop a biomimetic structure that...
One of the biological models presented in recent years to express the neuropathology of schizophrenia is based on an inactivated pathologic astrocyte in the tripartite synapse. In this study we developed a mathematical model of a tripartite synapse capable of expressing the pathologic behavior of the synapse under the aforementioned condition. Our results indicate that under pathologic conditions,...
Glutamate and dopamine hypothesizes are known in the pathophysiology of schizophrenia. Some recent experiments suggest that there is an interaction between them. We proposed a mathematical model for some of the abnormalities of schizophrenia in the synaptic level. First, we developed a healthy single tripartite synapse and after that the model according to the schizophrenia was impaired. The tripartite...
Behavioural evidence shows placebo modulations of motor performance. Different studies in this field supported that placebo improves sensible physical parameters such as force and speed. However, the effect of placebo on more complicated indices like harmony and symmetry of movement during gait has not been studied up to today. We explored if a placebo modulation of motor performance could affect...
In this paper, a computational algorithm is introduced to generate energy efficient gait patterns. Each space cycle of gait has been decomposed to several phases, and boundaries of each phase are called via points. The algorithm uses six universal movement elements [1] together with kinematic information of the physical system at via points. We also developed an optimization procedure to obtain energy...
Experimental studies revealed spatial navigation impairments in schizophrenic patients. Both human and animal subjects exhibited diminished navigation performances compared to control ones. In brain, hippocampus is believed to be more involved in navigation and memory. In the pathology of schizophrenia, neural mechanisms especially synaptic transmission of hippocampal neurons change and functionalities...
Addiction is a chronic disorder whereby addicted individuals compulsively engage in drug seeking despite its negative consequences. Hippocampus has unavoidable role in addiction because of its importance in learning and memory. Any modification of hippocampal cells alters dopamine levels in NAc and firing rates of VTA dopaminergic cells. In order to have a better understanding of the addiction in...
Occurrence of seizure in some Alzheimer's disease (AD) patients suggests that the mechanisms involved in pathology of AD may also give rise to occurrence of neural hyperexcitability. Among the hallmarks of the AD is accumulation of amyloid beta (Aβ) peptide which has different effects on neural circuitry. Several observations indicate that most probably increase in Aβ results in structural and functional...
The basal ganglia play an important role in motor control and their malfunction is implicated in several disorders including Parkinson's disease (PD), in which dopamine concentration is greatly reduced. This is associated with changes in their firing patterns, evidenced by increase in firing rate of output nuclei of basal ganglia and synchronization between neurons of different micro-circuitry of...
There are several neuropsychological theories about the pathology of schizophrenia, one of which is the glutamate theory. This theory suggests that hypofunction of NMDA receptors, which may be caused by dysfunction or dysregulation of NMDA receptors, leads to symptoms of schizophrenia. On the other hand, inactivated astrocyte and decreased levels of D-Serine concentration have also been considered...
In the present study, we propose a mathematical model to describe the key role of postsynaptic calcium concentration in Late Long-Term Potentiation (L-LTP) induction. This model is developed based on physiological facts of a typical CA3-CA1 tripartite synapse. In the proposed model, each astrocyte has a bidirectional signaling with pre synaptic neuron and based on its intracellular calcium oscillations...
In this work we propose a model to describe impairment of Long-Term Potentiation (LTP) due to Amyloid Beta (Aβ) accumulation during Alzheimer's Disease (AD) in hippocampus. The model embeds astrocyte-neuron interactions and Spike Timing-Dependent Plasticity (STDP) in CA3-CA1 synapses. In our proposed model, considering physiological facts, each astrocyte has a bidirectional signaling with four neurons,...
In this work we propose a biophysical neural network model to investigate some of the impacts of the Alzheimer's disease (AD) on spatial navigation in a simulated rodent. The model is a hybrid model developed based on physiological and functional description of neuronal networks in the hippocampus engaged in place field formation. The model of hippocampal network takes into account both anatomical...
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