scholarly journals Original article Non-woven nanofiber mats – a new perspective for experimental studies of the central nervous system?

2014 ◽  
Vol 4 ◽  
pp. 407-416 ◽  
Author(s):  
Janina Rafalowska ◽  
Dorota Sulejczak ◽  
Stanisław J. Chrapusta ◽  
Roman Gadamski ◽  
Anna Taraszewska ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Experimental Studies ◽  
The Central Nervous System ◽  
New Perspective ◽  
Nanofiber Mats

scholarly journals Detecting task-dependent modulation of spatiotemporal module via tensor decomposition: application to kinematics and EMG data for walking and running at various speed

2019 ◽  
Author(s):  
Ken Takiyama ◽  
Hikaru Yokoyama ◽  
Naotsugu Kaneko ◽  
Kimitaka Nakazawa
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Tensor Decomposition ◽  
Fundamental Question ◽  
Time Varying ◽  
Related Research ◽  
Research Areas ◽  
The Central Nervous System ◽  
Motor Neuroscience ◽  
New Perspective

AbstractHow the central nervous system (CNS) controls many joints and muscles is a fundamental question in motor neuroscience and related research areas. An attractive hypothesis is the module hypothesis: the CNS controls groups of joints or muscles (i.e., spatial modules) while providing time-varying motor commands (i.e., temporal modules) to the spatial modules rather than controlling each joint or muscle separately. Another fundamental question is how the CNS generates numerous repertories of movement patterns. One hypothesis is that the CNS modulates the spatial and/or temporal modules depending on the required tasks. It is thus essential to quantify the spatial module, the temporal module, and the task-dependent modulation of those modules. Although previous methods attempted to quantify these aspects, they considered the modulation in only the spatial or temporal module. These limitations were possibly due to the constraints inherent to conventional methods for quantifying the spatial and temporal modules. Here, we demonstrate the effectiveness of tensor decomposition in quantifying the spatial module, the temporal module, and the task-dependent modulation of these modules without such limitations. We further demonstrate that the tensor decomposition provides a new perspective on the task-dependent modulation of spatiotemporal modules: in switching from walking to running, the CNS modulates the peak timing in the temporal module while recruiting proximal muscles in the corresponding spatial module.Author summaryThere are at least two fundamental questions in motor neuroscience and related research areas: 1) how does the central nervous system (CNS) control many joints and muscles and 2) how does the CNS generate numerous repertories of movement patterns. One possible answer to question 1) is that the CNS controls groups of joints or muscles (i.e., spatial modules) while providing time-varying motor commands (i.e., temporal modules) to the spatial modules rather than controlling each joint or muscle separately. One possible answer to question 2) is that the CNS modulates the spatial and/or temporal module depending on the required tasks. It is thus essential to quantify the spatial module, the temporal module, and the task-dependent modulation of those modules. Here, we demonstrate the effectiveness of tensor decomposition in quantifying the modules and those task-dependent modulations while overcoming the shortcomings inherent to previous methods. We further show that the tensor decomposition provides a new perspective on how the CNS switches between walking and running. The CNS modulated the peak timing in the temporal module while recruiting proximal muscles in the corresponding spatial module.

scholarly journals A Fair and EMG-validated Comparison of Recruitment Criteria, Musculotendon Models and Muscle Coordination Strategies, for the Inverse-dynamics Based Optimization of Muscle Forces During Gait

2020 ◽  
Author(s):  
Florian MICHAUD ◽  
Mario Lamas ◽  
Urbano Lugrís ◽  
Javier Cuadrado
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cost Function ◽  
Inverse Dynamics ◽  
Experimental Studies ◽  
Motor Task ◽  
Muscle Coordination ◽  
Actuator Dynamics ◽  
Moment Arms ◽  
The Central Nervous System

Abstract Experimental studies and EMG collections suggest that a specific strategy of muscle coordination is chosen by the central nervous system to perform a given motor task. A popular mathematical approach for solving the muscle recruitment problem is optimization. Optimization-based methods minimize or maximize some criterion (objective function or cost function) which reflects the mechanism used by the central nervous system to recruit muscles for the movement considered. The proper cost function is not known a priori, so the adequacy of the chosen function must be validated according to the obtained results. In addition of the many criteria proposed, several physiological representations of the musculotendon actuator dynamics along with different musculoskeletal models can be found in the literature, which hinders the selection of the best neuromusculotendon model for each application. Seeking to provide a fair base for comparison, this study measures the efficiency and accuracy of: i) four different criteria; ii) one static and three physiological representations of the musculotendon actuator dynamics; iii) a synergy-based method; all of them within the framework of inverse-dynamics based optimization. Motion/force/EMG gait analyses were performed on ten healthy subjects. A musculoskeletal model of the right leg actuated by 43 Hill-type muscles was scaled to each subject and used to calculate joint moments, musculotendon kinematics and moment arms. Muscle activations were then estimated using the different approaches, and these estimates were compared with EMG measurements. Although similar results were obtained with all the methods, it must be pointed out that a higher complexity of the method does not guarantee better results, as the best correlations with experimental values were obtained with two simplified approaches.

scholarly journals Current Understanding of Central Nervous System Drainage Systems: Implications in the Context of Neurodegenerative Diseases

2020 ◽  
Vol 18 (11) ◽  
pp. 1054-1063 ◽  
Author(s):  
Vladimir N. Nikolenko ◽  
Marine V. Oganesyan ◽  
Angela D. Vovkogon ◽  
Arina T. Nikitina ◽  
Ekaterina A. Sozonova ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Neurodegenerative Diseases ◽  
Lymphatic Vessels ◽  
Basal Area ◽  
Waste Products ◽  
Glymphatic System ◽  
The Central Nervous System ◽  
New Perspective ◽  
And Function

Until recently, it was thought that there were no lymphatic vessels in the central nervous system (CNS). Therefore, all metabolic processes were assumed to take place only in the circulation of the cerebrospinal fluid (CSF) and through the blood-brain barrier’s (BBB), which regulate ion transport and ensure the functioning of the CNS. However, recent findings yield a new perspective: There is an exchange of CSF with interstitial fluid (ISF), which is drained to the paravenous space and reaches lymphatic nodes at the end. This circulation is known as the glymphatic system. The glymphatic system is an extensive network of meningeal lymphatic vessels (MLV) in the basal area of the skull that provides another path for waste products from CNS to reach the bloodstream. MLV develop postnatally, initially appearing around the foramina in the basal part of the skull and the spinal cord, thereafter sprouting along the skull’s blood vessels and spinal nerves in various areas of the meninges. VEGF-C protein (vascular endothelial growth factor), expressed mainly by vascular smooth cells, plays an important role in the development of the MLV. The regenerative potential and plasticity of MLV and the novel discoveries related to CNS drainage offer potential for the treatment of neurodegenerative diseases such as dementia, hydrocephalus, stroke, multiple sclerosis, and Alzheimer disease (AD). Herein, we present an overview of the structure and function of the glymphatic system and MLV, and their potential involvement in the pathology and progression of neurodegenerative diseases.

scholarly journals EXPERIMENTAL STUDIES OF THE VIRUS OF INFECTIOUS AVIAN ENCEPHALOMYELITIS

1939 ◽  
Vol 70 (6) ◽  
pp. 565-582 ◽  
Author(s):  
Peter K. Olitsky
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Experimental Studies ◽  
Vitreous Body ◽  
Host Susceptibility ◽  
Laboratory Animals ◽  
Blood Sucking ◽  
The Central Nervous System ◽  
Experimental Disease ◽  
Infective Agent

The results of investigations thus far carried out on experimental avian encephalomyelitis indicate that the virus of this newly described disease conforms to the group of definitely established viruses. It was essential to determine its taxonomy since the only prior record of its study (1) defines the infective agent as a virus because the usual cultural attempts failed to reveal a visible microorganism to be identified with it, and because the transmissible agent passed through Seitz and Berkefeld N filters. At the present time such determinants fail completely to satisfy the criteria for defining a virus and their acceptance would lead to the inclusion of certain filtrable microbic agents, difficult to reveal except by special cultural procedures, as viruses (10). The virus of avian encephalomyelitis is distinct from that of equine encephalomyelitis and is clearly a virus sui generis. The striking feature of its properties is its narrow range of host susceptibility—only the avian species are responsive to inoculation; ordinary laboratory animals are apparently resistant, even to large numbers of chicken cerebral infective doses. In addition, it is probable that its size is in the range of that of the equine virus. Studies also reveal that the virus is not easily sedimented by centrifugation (that is, at 5400 R.P.M. for one hour in the angle centrifuge and at 12,000 R.P.M. for one hour in the open air centrifuge) and is resistant to the action of glycerol and to drying. It is readily filtrable through Seitz one and two disc filters, through Berkefeld V and N candles, and is active in dilutions in broth up to 10–6. It passes through gradocol membranes of 73 mµ average pore diameter at least (the end-point has not as yet been definitely determined). An attack of the experimental disease leads to development of resistance to reinoculation and of antibodies in the serum. Old birds are reported as being refractory to infection, both in nature and in the laboratory (1, 2). Whether this resistance in mature animals is due to earlier exposure to infection, or to the development of structural or physiological barriers to invasion by the virus, remains still to be determined. Under experimental conditions, the route by which the virus acts uniformly to induce disease is the intracerebral. Yet in certain instances other peripheral ways of inoculation such as the intraperitoneal, subcutaneous, intradermal, intravenous, intramuscular, intrasciatic, may also be effective. Thus far, in limited experiments, feeding, or instilling nasally, or injecting into the vitreous body the infective agent has been ineffective. Whether the viral progression is axonal from peripheral sites is still to be determined; as should be also the question whether it multiplies in any of the organs other than the central nervous tissues. The virus was not detected in the blood during the period of incubation or during the acute phases of the experimental disease. So that unless it is found that other animals harbor the virus, or that still other sources of it exist as yet not disclosed, it is not likely that the disease is disseminated by a blood-sucking insect. The actual portal of entry and the factor in the spread of the disease in nature is still obscure, since the evidence here presented is still too incomplete to elucidate these problems. The pathological lesions induced are of interest. The neuronal reaction resembles that brought about by axonal disturbance (axon reaction, Nissl's or retrograde degeneration). The question may well be asked whether there may not be here an initial injury by the virus to the axonal process of the neuron, which in turn induces the retrograde changes in the cell body. This has as yet to be studied, as well as the possibility of viral progression along an axonal route with or without concurrent multiplication. The significance of the second major lesion in the central nervous system, namely, the generally marked perivascular reaction, is also still to be determined. Finally, the only observable and histopathological change in organs other than the central nervous tissues (in which we have not as yet noted the change) is in the hyperplasia of the normally present lymphoid islands. One is impressed by the prodigious numbers of lymphoid elements surrounding the vessels of the central nervous system and the question here is whether these hyperplastic areas serve as depots to supply the cells for this perivascular reaction.

scholarly journals Effects of Tibolone on the Central Nervous System: Clinical and Experimental Approaches

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Rodolfo Pinto-Almazán ◽  
Julia J. Segura-Uribe ◽  
Eunice D. Farfán-García ◽  
Christian Guerra-Araiza
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Postmenopausal Women ◽  
Neuronal Damage ◽  
Brain Plasticity ◽  
Hormone Replacement ◽  
Hot Flashes ◽  
Experimental Studies ◽  
Neuroprotective Effects ◽  
The Central Nervous System

Hormone replacement therapy (HRT) increases the risk of endometrial and breast cancer. A strategy to reduce this incidence is the use of tibolone (TIB). The aim of this paper was to address the effects of TIB on the central nervous system (CNS). For the present review, MEDLINE (via PubMed), LILACS (via BIREME), Ovid Global Health, SCOPUS, Scielo, and PsycINFO (ProQuest Research Library) electronic databases were searched for the results of controlled clinical trials on peri- and postmenopausal women published from 1990 to September 2016. Also, this paper reviews experimental studies performed to analyze neuroprotective effects, cognitive deficits, neuroplasticity, oxidative stress, and stroke using TIB. Although there are few studies on the effect of this hormone in the CNS, it has been reported that TIB decreases lipid peroxidation levels and improves memory and learning. TIB has important neuroprotective effects that could prevent the risk of neurodegenerative diseases in postmenopausal women as well as the benefits of HRT in counteracting hot flashes, improving mood, and libido. Some reports have found that TIB delays cognitive impairment in various models of neuronal damage. It also modifies brain plasticity since it acts as an endocrine modulator regulating neurotransmitters, Tau phosphorylation, and decreasing neuronal death. Finally, its antioxidant effects have also been reported in different animal models.

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