scholarly journals Lumbar corticospinal tract in rodents modulates sensory inputs but does not convey motor command

2020 ◽  
Author(s):  
Yunuen Moreno ◽  
Charlotte Bichara ◽  
Philippe Isope ◽  
Matilde Cordero-Erausquin
Keyword(s):  
Spinal Cord ◽  
Corticospinal Tract ◽  
Motor Command ◽  
Primary Afferent Depolarization ◽  
Main Role ◽  
Main Function ◽  
Spinal Motoneurons ◽  
Sensory Inputs ◽  
Lumbar Level

It is generally assumed that the main function of the corticospinal tract (CST) is to convey motor commands to bulbar or spinal motoneurons. Yet the CST has also been shown to modulate sensory signals at their entry point in the spinal cord, through primary afferent depolarization (PAD). By sequentially investigating different routes of corticofugal pathways, we here demonstrate that motor and PAD commands in mice belong to segregated paths within the CST. PAD is carried out exclusively by the CST via a population of lumbar interneurons located in the deep dorsal horn. In contrast, the cortex conveys the motor command via a relay in the upper spinal cord or supraspinal motor centers. At lumbar level, the main role of the CST is thus the modulation of sensory inputs, which is an essential component of the selective tuning of sensory feedback, to ensure well-coordinated and skilled movement.

scholarly journals The corticospinal tract primarily modulates sensory inputs in the mouse lumbar cord

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Yunuen Moreno-Lopez ◽  
Charlotte Bichara ◽  
Gilles Delbecq ◽  
Philippe Isope ◽  
Matilde Cordero-Erausquin
Keyword(s):  
Spinal Cord ◽  
Corticospinal Tract ◽  
Motor Command ◽  
Primary Afferent Depolarization ◽  
Main Role ◽  
Main Function ◽  
Sensory Modulation ◽  
Sensory Inputs ◽  
Lumbar Level ◽  
Electrophysiological Recordings

It is generally assumed that the main function of the corticospinal tract (CST) is to convey motor commands to bulbar or spinal motoneurons. Yet the CST has also been shown to modulate sensory signals at their entry point in the spinal cord through primary afferent depolarization (PAD). By sequentially investigating different routes of corticofugal pathways through electrophysiological recordings and an intersectional viral strategy, we here demonstrate that motor and sensory modulation commands in mice belong to segregated paths within the CST. Sensory modulation is executed exclusively by the CST via a population of lumbar interneurons located in the deep dorsal horn. In contrast, the cortex conveys the motor command via a relay in the upper spinal cord or supraspinal motor centers. At lumbar level, the main role of the CST is thus the modulation of sensory inputs, which is an essential component of the selective tuning of sensory feedback used to ensure well-coordinated and skilled movement.

Properties of Primary Sensory (Lemniscal) Synapses in the Ventrobasal Thalamus and the Relay of High-Frequency Sensory Inputs

2002 ◽  
Vol 87 (2) ◽  
pp. 946-953 ◽  
Author(s):  
Manuel A. Castro-Alamancos
Keyword(s):  
High Frequency ◽  
Sensory Information ◽  
Main Role ◽  
Medial Lemniscus ◽  
Afferent Pathways ◽  
Postsynaptic Potentials ◽  
Sensory Inputs ◽  
Ventrobasal Thalamus

The main role of the thalamus is to relay sensory inputs to the neocortex. In the primary somatosensory thalamus (ventrobasal thalamus), sensory inputs deliver tactile information through the medial lemniscus tract. The transmission of sensory information through this pathway is affected by behavioral state. For instance, the relay of high-frequency somatosensory inputs through the thalamus is suppressed during anesthesia or quiescent states but allowed during behaviorally activated states. This change may be due to the effects of modulators on the efficacy of lemniscal synapses. Here I show that lemniscal synapses of adult rodents studied in vitro produce large amplitude-highly secure unitary excitatory postsynaptic potentials (EPSPs), which depress in response to repetitive stimulation at frequencies >2 Hz. Acetylcholine and norepinephrine, which are important thalamic modulators, have no effect on the efficacy of lemniscal EPSPs but reduce evoked inhibitory postsynaptic potentials and corticothalamic EPSPs. Although acetylcholine and norepinephrine do not affect lemniscal synapses, the postsynaptic depolarization they produce on thalamocortical neurons serves to warrant the relay of lemniscal inputs at high-frequency rates by bringing the depressed lemniscal EPSPs close to firing threshold. In conclusion, acetylcholine and norepinephrine released during activated states selectively enhance sensory transmission through the lemniscal pathway by depolarizing thalamocortical neurons and simultaneously depressing the other afferent pathways.

scholarly journals Modelling spinal locomotor circuits for movements in developing zebrafish

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Yann Roussel ◽  
Stephanie F Gaudreau ◽  
Emily R Kacer ◽  
Mohini Sengupta ◽  
Tuan V Bui
Keyword(s):  
Spinal Cord ◽  
Synaptic Transmission ◽  
Motor Command ◽  
Rhythm Generation ◽  
Spinal Neurons ◽  
Firing Patterns ◽  
Locomotor Control ◽  
Musculoskeletal Models ◽  
Phase Relationships

Many spinal circuits dedicated to locomotor control have been identified in the developing zebrafish. How these circuits operate together to generate the various swimming movements during development remains to be clarified. In this study, we iteratively built models of developing zebrafish spinal circuits coupled to simplified musculoskeletal models that reproduce coiling and swimming movements. The neurons of the models were based upon morphologically or genetically identified populations in the developing zebrafish spinal cord. We simulated intact spinal circuits as well as circuits with silenced neurons or altered synaptic transmission to better understand the role of specific spinal neurons. Analysis of firing patterns and phase relationships helped identify possible mechanisms underlying the locomotor movements of developing zebrafish. Notably, our simulations demonstrated how the site and the operation of rhythm generation could transition between coiling and swimming. The simulations also underlined the importance of contralateral excitation to multiple tail beats. They allowed us to estimate the sensitivity of spinal locomotor networks to motor command amplitude, synaptic weights, length of ascending and descending axons, and firing behaviour. These models will serve as valuable tools to test and further understand the operation of spinal circuits for locomotion.

ИЛИМИЙ ИЗИЛДӨӨЛӨРДYН НЕГИЗИНДЕГИ СТЕРЕОТИПТЕРДИН ФУНКЦИЯЛАРЫ

2020 ◽  
pp. 12-15
Author(s):  
Айзат Бутешова
Keyword(s):  
Main Role ◽  
Self Awareness ◽  
Main Function ◽  
Ethnic Stereotypes ◽  
Cross Cultural Communication ◽  
The Subject ◽  
The Difference ◽  
And Linguistics ◽  
Social Stereotype

Аннотация: Бул илимий макаланын негизги максаты – стереотиптердин тил илиминдеги жана лингвистикадагы негизги ролун, алардын негизги функцияларын бөлүп көрсөтүү, стереотип менен адатка айланган ынанычтын айырмасын аныктоо. Буга байланыштуу стереотип, этностереотип, мента- литет жана адатка айланган ынаныч сыяктуу түшүнүктөр дифференцияланды. Изилдөө процессинин жүрүшүндө стереотиптердин пайда болуу себептери такталып, аларды алып жүрүүчүлөр, ошондой эле этностереотиптердин булактары аныкталды. Окумуштуу-тилчилер изилдөөлөөрүндө стереотиптер аркылуу адам дүйнөнү чектөөсүз толугу менен таанып билерин баса белгилешти. Стереотиптердин функцияларын ар башка багыттардагы көптөгөн илимпоздор карашкан, өз изилдөө предметине жараша стереотиптердин бири-бирине кандайдыр бир байланышта болгон ар кандай функциялары белгиленип аныкталган. Макалада ар түрдүү мисалдардын негизинде стереотиптер эмоциялык боёкко, чындыкка жана негиздүүлүккө ээ экендиги көрсөтүлдү. Демек, этностереотиптердин негизги функциясы болуп элдин өзү тууралуу көз карашын коргоо, өз маданиятын жана өзүн өзү таанып билүү деңгээлин жогорулатуу эсептелет. Түйүндүү сөздөр: стереотип, коомдук стереотип, этномаданияттык стереотип, коом аралык баарлашуу. Аннотация: Целью данной статьи является выявление основной роли стереотипов в языкознании и лингвистике, выделение их основной функции, определение разницы между стереотипами и предрассудками. В связи с этим были дифференцированы такие понятия как стереотип, этностереотип, менталитет, предрассудки. В процессе проведенного исследования были установлены причины возникновения стереотипов, его носители, а также источники этностереотипов. Ученые-лингвисты в своих исследованиях подчеркивают, что благодаря стереотипам человек узнает мир полным без границ. Функции стереотипов рассматривались многими учеными разных направлений, и в зависимости от предмета исследований ими были выделены разные функции стереотипов, в какой-то мере перекликающихся между собой. В статье на основе примеров показано, что стереотипы обладают эмоциональной окрашенностью, истинностью и обоснованностью. Следовательно, главной функцией этнических стереотипов является защита представлений народа о самом себе, о своей культуре, и повышение уровня самосознания этноса. Ключевые слова: стереотип, социальный стереотип, этнокультурный стереотип, межкультурная коммуникация, предрассудки. Annotation: The purpose of this article is to identify the main role of stereotypes in linguistics and linguistics, highlight their main functions, determine the difference between stereotypes and prejudices. In this regard, concepts such as stereotype, ethnostereotype, mentality, and prejudice were differentiated. In the process of the study, the causes of stereotypes, its carriers, as well as the sources of ethnostereotypes were established. Scientists - linguists in their studies emphasize that thanks to stereotypes a person learns the world complete without borders. The functions of stereotypes were considered by many scientists of different directions, and depending on the subject of research, they identified different functions of stereotypes, to some extent overlapping with each other. Based on examples, the article shows that stereotypes have emotional coloring, truthfulness and validity. Consequently, the main function of ethnic stereotypes is to protect the people's perceptions of themselves, their culture, and increase the level of self-awareness of the ethnic group. Key words: stereotype, social stereotype, ethno cultural stereotype, cross-cultural communication, prejudices.

Role of spectrin in membrane fusion and in shape change of human erythrocyte ghost

1978 ◽  
Vol 36 (2) ◽  
pp. 328-329
Author(s):  
Hideo Hayashi ◽  
Yoshikazu Hirai ◽  
John T. Penniston
Keyword(s):  
Conformational Changes ◽  
Human Erythrocyte ◽  
Shape Change ◽  
Membrane Surface ◽  
Slight Modification ◽  
Active Role ◽  
Main Role ◽  
Bank Blood ◽  
Human Erythrocyte Ghost

Spectrin is a membrane associated protein most of which properties have been tentatively elucidated. A main role of the protein has been assumed to give a supporting structure to inside of the membrane. As reported previously, however, the isolated spectrin molecule underwent self assemble to form such as fibrous, meshwork, dispersed or aggregated arrangements depending upon the buffer suspended and was suggested to play an active role in the membrane conformational changes. In this study, the role of spectrin and actin was examined in terms of the molecular arrangements on the erythrocyte membrane surface with correlation to the functional states of the ghosts.Human erythrocyte ghosts were prepared from either freshly drawn or stocked bank blood by the method of Dodge et al with a slight modification as described before. Anti-spectrin antibody was raised against rabbit by injection of purified spectrin and partially purified.

Mesophyll conductance: the leaf corridors for photosynthesis

2020 ◽  
Vol 48 (2) ◽  
pp. 429-439 ◽  
Author(s):  
Jorge Gago ◽  
Danilo M. Daloso ◽  
Marc Carriquí ◽  
Miquel Nadal ◽  
Melanie Morales ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Main Role ◽  
Mesophyll Conductance ◽  
Future Studies ◽  
Cell Structures ◽  
Leaf Tissues ◽  
Change Framework ◽  
Chloroplast Stroma

Besides stomata, the photosynthetic CO2 pathway also involves the transport of CO2 from the sub-stomatal air spaces inside to the carboxylation sites in the chloroplast stroma, where Rubisco is located. This pathway is far to be a simple and direct way, formed by series of consecutive barriers that the CO2 should cross to be finally assimilated in photosynthesis, known as the mesophyll conductance (gm). Therefore, the gm reflects the pathway through different air, water and biophysical barriers within the leaf tissues and cell structures. Currently, it is known that gm can impose the same level of limitation (or even higher depending of the conditions) to photosynthesis than the wider known stomata or biochemistry. In this mini-review, we are focused on each of the gm determinants to summarize the current knowledge on the mechanisms driving gm from anatomical to metabolic and biochemical perspectives. Special attention deserve the latest studies demonstrating the importance of the molecular mechanisms driving anatomical traits as cell wall and the chloroplast surface exposed to the mesophyll airspaces (Sc/S) that significantly constrain gm. However, even considering these recent discoveries, still is poorly understood the mechanisms about signaling pathways linking the environment a/biotic stressors with gm responses. Thus, considering the main role of gm as a major driver of the CO2 availability at the carboxylation sites, future studies into these aspects will help us to understand photosynthesis responses in a global change framework.

Questions on the role of biofilms for the adaptation of microorganisms to unfavorable environmental factors by the example of P. aeruginosa

2020 ◽  
Vol 99 (4) ◽  
pp. 379-383
Author(s):  
Vasily N. Afonyushkin ◽  
N. A. Donchenko ◽  
Ju. N. Kozlova ◽  
N. A. Davidova ◽  
V. Yu. Koptev ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Environmental Factors ◽  
Barrier Function ◽  
Infectious Agent ◽  
Antagonistic Activity ◽  
The Body ◽  
Main Function ◽  
Pathogenic Potential ◽  
The Face

Pseudomonas aeruginosa is a widely represented species of bacteria possessing of a pathogenic potential. This infectious agent is causing wound infections, fibrotic cystitis, fibrosing pneumonia, bacterial sepsis, etc. The microorganism is highly resistant to antiseptics, disinfectants, immune system responses of the body. The responses of a quorum sense of this kind of bacteria ensure the inclusion of many pathogenicity factors. The analysis of the scientific literature made it possible to formulate four questions concerning the role of biofilms for the adaptation of P. aeruginosa to adverse environmental factors: Is another person appears to be predominantly of a source an etiological agent or the source of P. aeruginosa infection in the environment? Does the formation of biofilms influence on the antibiotic resistance? How the antagonistic activity of microorganisms is realized in biofilm form? What is the main function of biofilms in the functioning of bacteria? A hypothesis has been put forward the effect of biofilms on the increase of antibiotic resistance of bacteria and, in particular, P. aeruginosa to be secondary in charcter. It is more likely a biofilmboth to fulfill the function of storing nutrients and provide topical competition in the face of food scarcity. In connection with the incompatibility of the molecular radii of most antibiotics and pores in biofilm, biofilm is doubtful to be capable of performing a barrier function for protecting against antibiotics. However, with respect to antibodies and immunocompetent cells, the barrier function is beyond doubt. The biofilm is more likely to fulfill the function of storing nutrients and providing topical competition in conditions of scarcity of food resources.

Sports Photography and Historical Development

2018 ◽  
Vol 5 (1) ◽  
pp. 93-115
Author(s):  
Miloš Stamenković
Keyword(s):  
Historical Development ◽  
Emotional Reaction ◽  
Main Role ◽  
Primary Role

SummarySports photography undoubtedly has a significant place in sports press and publicism. It’s main and primary role is to present sports to the readers as art, which it is. Sport is characterized by dynamic and varied movements, and the main role of sports photography is reflected in the fact that it is in this way that sport shows its essence. Having in mind that photography tells more than a thousand words it sends a clear message to the reader as well to people who are informed about events via sports portals. Sports photography is a multidimensional art for many reasons. When we say “multi”, it primarily refers to a wider range that sports photography has to offer, which means sports photography is not only directed at presenting athletes on the move and the main actors who contribute to achieving the results by their engagement – it also has the role of sports “psychophotography” which is an analysis and capture of the emotional reaction of an athlete after winning or losing from the opposing team.

Problems and prospects for the Russian banking supervision development in modern conditions

2020 ◽  
Vol 26 (6) ◽  
pp. 1283-1296
Author(s):  
K.A. Omarieva ◽  
P.G. Isaeva
Keyword(s):  
Banking System ◽  
Main Role ◽  
Banking Supervision ◽  
Monetary System ◽  
The Russian Federation ◽  
Document Flow ◽  
Development Methods ◽  
Further Development ◽  
Development Prospects

Subject. The article addresses problems and prospects for the banking supervision development in the Russian Federation under modern conditions. Objectives. We review the essence and methods of organization of the banking supervision, and identify the main problems and prospects for its development. Methods. To provide valid, reliable and reasoned recommendations, we apply normative and integrated approaches to the study of the banking supervision effectiveness in the current circumstances. Results. The paper investigates main problems and development prospects for the Russian banking supervision. The essential importance of supervision comes from the main role of the banking system in maintaining accounts of economic entities and making settlements. Even minor failures or delays in operations can lead to negative outcomes and disastrous consequences for the entire monetary system and the national economy. Therefore, we highlight issues that require attention, and make proposals for further development of the banking supervision. Conclusions. In the context of dynamically developing economy, the banking practice is becoming more complex. As a result, there is a need for new financial instruments that can reduce risks, increase the speed and efficiency of operations and document flow, and help achieve the world levels of introduced standards.

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