MotoneuroneLes motoneurones constituent la voie de sortie du système nerveux central ou la voie finale de tout acte moteur. Les corps cellulaires des motoneurones sont situés soit dans le tronc cérébral, soit dans la corne ventrale de la substance grise de la moelle épinière. Chaque motoneurone possède un axone qui part du système nerveux central pour innerver les fibres musculaires d'un muscle. L'ensemble constitué par un motoneurone et les fibres musculaires qu'il innerve constitue une unité motrice.
Pioneer axonPioneer axon is the classification given to axons that are the first to grow in a particular region. They originate from pioneer neurons, and have the main function of laying down the initial growing path that subsequent growing axons, dubbed follower axons, from other neurons will eventually follow. Several theories relating to the structure and function of pioneer axons are currently being explored. The first theory is that pioneer axons are specialized structures, and that they play a crucial role in guiding follower axons.
Facteur neurotropheLes facteurs neurotrophes ou neurotrophiques forment une famille de protéines responsables de la croissance et de la survie des neurones en développement et de l'entretien des neurones matures. Des recherches récentes ont prouvé qu'ils sont capables de faire repousser des neurones endommagés, in vitro et in vivo. Les facteurs neurotrophes sont souvent libérés par le tissu cible afin de guider la croissance des axones en développement. Chaque famille a sa propre signalisation mais les réponses cellulaires se chevauchent.
UNC-5UNC-5 is a receptor for netrins including UNC-6. Netrins are a class of proteins involved in axon guidance. UNC-5 uses repulsion to direct axons while the other netrin receptor UNC-40 attracts axons to the source of netrin production. The term netrin was first used in a study done in 1990 in Caenorhabditis elegans and was called UNC-6. Studies performed on rodents in 1994 have determined that netrins are vital to guidance cues. The vertebrate orthologue of UNC-6, netrin-1 was determined to be a key guidance cue for axons moving toward the ventral midline in the rodent embryo spinal cord.
Nociceptionvignette|Fibres nerveuses sensorielles stimulées au-delà de l'intensité nocive provoquant une douleur nociceptive. La nociception est une fonction défensive présente chez les vertébrés ainsi que chez les invertébrés. C'est une fonction permettant l'intégration, au niveau du système nerveux central, d'un stimulus potentiellement nocif via l'activation des nocicepteurs cutanés, viscéraux, musculaires et articulaires. Le transport de l'information sensorielle par les nerfs se fait de la périphérie (lieu de transduction d'un message potentiellement nocif en nociception) jusqu'au thalamus.
Focal adhesionIn cell biology, focal adhesions (also cell–matrix adhesions or FAs) are large macromolecular assemblies through which mechanical force and regulatory signals are transmitted between the extracellular matrix (ECM) and an interacting cell. More precisely, focal adhesions are the sub-cellular structures that mediate the regulatory effects (i.e., signaling events) of a cell in response to ECM adhesion. Focal adhesions serve as the mechanical linkages to the ECM, and as a biochemical signaling hub to concentrate and direct numerous signaling proteins at sites of integrin binding and clustering.
Cell migrationCell migration is a central process in the development and maintenance of multicellular organisms. Tissue formation during embryonic development, wound healing and immune responses all require the orchestrated movement of cells in particular directions to specific locations. Cells often migrate in response to specific external signals, including chemical signals and mechanical signals. Errors during this process have serious consequences, including intellectual disability, vascular disease, tumor formation and metastasis.
Nerve injuryNerve injury is an injury to nervous tissue. There is no single classification system that can describe all the many variations of nerve injuries. In 1941, Seddon introduced a classification of nerve injuries based on three main types of nerve fiber injury and whether there is continuity of the nerve. Usually, however, peripheral nerve injuries are classified in five stages, based on the extent of damage to both the nerve and the surrounding connective tissue, since supporting glial cells may be involved.
NerfUn nerf est un organe de forme linéaire, présent dans le corps de la plupart des animaux eumétazoaires (Eumetazoa, ou métazoaires supérieurs), dont les mammifères et l'homme. En neuroanatomie, un nerf désigne un regroupement d'axones distinct traversant un tissu. Ces axones sont issus de neurones dont les corps cellulaires sont le plus souvent regroupés en ganglion. Les nerfs et les ganglions sont les composants anatomiques de base d'un système nerveux.
Neuronal ensembleA neuronal ensemble is a population of nervous system cells (or cultured neurons) involved in a particular neural computation. The concept of neuronal ensemble dates back to the work of Charles Sherrington who described the functioning of the CNS as the system of reflex arcs, each composed of interconnected excitatory and inhibitory neurons. In Sherrington's scheme, α-motoneurons are the final common path of a number of neural circuits of different complexity: motoneurons integrate a large number of inputs and send their final output to muscles.
