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Neurology. Wallerian degeneration is an active process of degeneration that results when a nerve fiber is cut or crushed and the part of the axon distal to the injury (which in most cases is farther from the neuron 's cell body) degenerates. [1] A related process of dying back or retrograde degeneration known as 'Wallerian-like degeneration ...
Slower degeneration of the distal segment than that which occurs in the peripheral nervous system also contributes to the inhibitory environment because inhibitory myelin and axonal debris are not cleared away as quickly. All these factors contribute to the formation of what is known as a glial scar, which axons cannot grow across. [9]
The three models explaining synaptic pruning are axon degeneration, axon retraction, and axon shedding. In all cases, the synapses are formed by a transient axon terminal, and synapse elimination is caused by the axon pruning. Each model offers a different method in which the axon is removed to delete the synapse.
When the axon is torn, Wallerian degeneration, in which the part of the axon distal to the break degrades, takes place within one to two days after injury. [26] The axolemma disintegrates, [ 26 ] myelin breaks down and begins to detach from the cell in an anterograde direction (from the body of the cell toward the end of the axon), [ 27 ] and ...
Axonal transport can be disrupted by a variety of mechanisms including damage to: kinesin and cytoplasmic dynein, microtubules, cargoes, and mitochondria. [25] When axonal transport is severely disrupted a degenerative pathway known as Wallerian-like degeneration is often triggered. [71]
The white space represents a disruption of the nerve fibers, resulting in a loss of nerve supply to the muscle fibers. Denervation is any loss of nerve supply regardless of the cause. If the nerves lost to denervation are part of the neuronal communication to a specific function in the body then altered or a loss of physiological functioning ...
Axon, endo-, peri-, and epineurium transected. Neurotmesis may be partial or complete. Other characteristics: distal Wallerian degeneration; partial or complete connective tissue lesion; severe sensory-motor problems and autonomic function defect; nerve conduction distal to the site of injury absent (3 to 4 days after lesion)
Alcoholic polyneuropathy is a neurological disorder in which peripheral nerves throughout the body malfunction simultaneously. It is defined by axonal degeneration in neurons of both the sensory and motor systems and initially occurs at the distal ends of the longest axons in the body.