Retrograde axonal transport

Myelin is modified plasma membrane. Myelin of the PNS resembles that of the CNS with respect to lipid composition. There is an enrichment in such specialized lipids as cerebroside and ethanolamine plasmalogen, and the high content of cholesterol plays an important role in control of membrane fluidity. The protein composition of PNS myelin is, however, distinct from that of CNS myelin. A single protein, P0, accounts for half of all protein of PNS myelin. Of the other proteins present, most are expressed in the CNS as well as the PNS but in quantitatively different amounts. Prominent among these proteins are myelin basic proteins and myelin-associated glycoprotein. 

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Neuroanatomists have taken advantage of the phenomenon of fast retrograde transport to locate remote nerve cell bodies in the CNS of an experimental animal that are connected to an identified axonal fiber tract whose origin is uncertain. The tracer material [purified horseradish peroxidase (HRP) enzyme] is injected in the region of the axon terminals, where it is taken up by endocytosis and then is carried by retrograde axonal transport over a period of several hours to days back to the nerve cell body. The animal is sacrificed, and the enzyme tracer is localized by staining thin sections of the brain for peroxidase activity. 

Details of the mechanisms by which endocytosed material moves from the early to the late and lysosomal compartment are still poorly understood. However, portions of the EEs tubulovesicular structures may be actively transported along microtubules towards the perinuclear region of the cell in both neurons and non-neuronal cells. These endosomes on the move may enclose invaginated membranes and also internally bud off vesicles. For that reason, these complex structures are called multivesicular bodies (MVBs) [76]. Material returning by retrograde axonal transport to the neuronal cell body includes many MVBs [67]. The eventual fate of these structures may vary. Some MVBs may fuse with LEs or they may fuse with each... 

Dynein Motor protein mediating microtubule-based synaptic vesicle transport. May be involved in retrograde axonal transport to the cell body. 

The receptor for NGF is TrkA, a 140 kDa cell surface protein that specifically binds NGF, but not other neurotrophins [5, 6, 9]. TrkA is expressed on the neuronal cell body and on neuronal processes. In its action as a target-derived trophic factor, NGF is secreted within the target organ and it then binds to TrkA receptors present on the growing neuronal process or synapse. The NGF-TrkA complex is then internalized and subsequently translocated to the cell body by retrograde axonal transport. In those cells that respond to NGF through autocrine or paracrine mechanisms, the growth factor can bind to any of the widely distributed TrkA molecules on the neuronal membrane. 

A number of studies have implicated cytoplasmic dynein as playing a role in retrograde axonal transport [11, 39]. In vitro motility studies demonstrate that cytoplasmic dynein generates force towards the minus ends of MTs consistent with a retrograde motor. Dynein immu-noreactivities have been associated with MBOs and... 

Grofova, I. (1975) The identification of striatal and pallidal neurons projecting to substantia nigra. An experimental study by means of retrograde axonal transport of horseradish peroxidase. Brain Res 91 286-291. 

Moos T. 1995. Age-dependent uptake and retrograde axonal transport of exogenous albumin and transferrin in rat motor neurons. Brain Res 672 14-23. 

Studies in experimental and chemical neuroanatomy underwent then, as it frequently happens in scientific research, a sudden acceleration. Retrograde axonal transport was discovered on the basis of the finding that proteins, such as the enzyme horseradish peroxidase (HRP), are retrogradely transported from axon terminals to their parent neuronal cell bodies (Kristensson and Olsson, 1971). The modern era of neuroanatomy... 

Kristensson K, Olsson Y (1971) Retrograde axonal transport of protein. Brain Res 29 363-365. 

Kuypers HGJM, Catsman-Berrevoets CE, Padt RE (1977) Retrograde axonal transport of fluorescent substances in the rat s forebrain. Neurosci Lett 6 127-135. 

Kuypers HGJM, Kievit J, Groen-Klevant AC (1974) Retrograde axonal transport of horseradish peroxidase in rat s forebrain. Brain Res 67 211-218. 

LaVail JH, LaVail MM (1972) Retrograde axonal transport in the central nervous system. Science 776 1416-1417. 

Laduron PM (1999) Functional consequences of retrograde axonal transport of receptor-bound neurotensin. Trends Pharmacol Sci 76 338-343. 

Sorting to the final destination TeTx is translocated predominantly by retrograde axonal transport to the axodendritic area of the motoneurons in the spinal cord. Here, the toxin is released, probably by a transcytotic mechanism, crosses the synaptic cleft. 

Mazarakis ND, Azzouz M, Rohll JB, El-lard FM, Wilkes FJ, et al. 2001. Rabies virus glycoprotein pseudotyping of lentiviral vectors enables retrograde axonal transport and access to the nervous system after peripheral delivery. Hum. Mol. Genet. 10 2109-21... 

GioUi, R. A., Blanks, R. H. I., Torigoe, Y, and WiUiams, D. D. (1985). Projections of medial terminal accessory optic nucleus, ventral tegmental nuclei, and substantia nigra of rabbit and rat as studied by retrograde axonal transport of horseradish peroxidase. J. Comp. Neurol. 232(1), 99-116. 

Fabian, R. H., Retrograde axonal transport and transcytosis of immunoglobulins implications for the pathogenesis of autoimmune motor neuron disease, Adv. Neurol., 56, 433, 1991. 

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