Emergence of axons from distal dendrites of adult mammalian neurons following a permanent axotomy. Export

@article{citeulike:3212193, abstract = {The distinctive features of axons and dendrites divide most neurons into two compartments. This polarity is fundamental to the ability of most neurons to integrate synaptic signals and transmit action potentials. It is not known, however, if the polarity of neurons in the adult mammalian nervous system is fixed or plastic. Following axotomy, some distal dendrites of neck motoneurons in the adult cat give rise to unusual processes that, at a light microscopic level, resemble axons (Rose, P.K. \& Odlozinski, M., J. Comp. Neurol., 1998, 390, 392). The goal of the present experiments was to characterize these unusual processes using well-established ultrastructural and molecular criteria that differentiate dendrites and axons. These processes were immunoreactive for growth-associated protein-43 (GAP-43), a protein that is normally confined to axons. In contrast, immunoreactivity for a protein that is widely used as a marker for dendrites, microtubule-associated protein (MAP)-2a/b, could not be detected in the unusual distal arborizations. At the electron microscopic level, unusual distal processes contained dense collections of neurofilaments and were frequently myelinated. These molecular and structural characteristics are typical of axons and suggest that the polarity of adult neurons in the mammalian nervous system can be disrupted by axotomy. If this transformation in neuronal polarity is common to other types of neurons, axon-like processes emerging from distal dendrites may represent a mechanism for replacing connections lost due to injury. Alternatively, the connections formed by these axons may be aberrant and therefore maladaptive.}, address = {CIHR Group in Sensory-Motor Systems, Department of Physiology, Queen's University, Kingston, Ont., Canada. ken@biomed.queensu.ca}, author = {Rose, P. K. and MacDermid, V. and Joshi, M. and Neuber-Hess, M.}, citeulike-article-id = {3212193}, citeulike-linkout-0 = {http://view.ncbi.nlm.nih.gov/pubmed/11285014}, citeulike-linkout-1 = {http://www.hubmed.org/display.cgi?uids=11285014}, comment = {using cats, axotomy makes axons grow from dista dendrites of motor neurones.}, issn = {0953-816X}, journal = {The European journal of neuroscience}, keywords = {axon, dendrite, neuron, polarity}, month = {March}, number = {6}, pages = {1166--1176}, posted-at = {2008-09-10 13:38:24}, priority = {0}, title = {Emergence of axons from distal dendrites of adult mammalian neurons following a permanent axotomy.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/11285014}, volume = {13}, year = {2001} }

TY - JOUR ID - citeulike:3212193 L3 - citeulike-article-id:3212193 N2 - The distinctive features of axons and dendrites divide most neurons into two compartments. This polarity is fundamental to the ability of most neurons to integrate synaptic signals and transmit action potentials. It is not known, however, if the polarity of neurons in the adult mammalian nervous system is fixed or plastic. Following axotomy, some distal dendrites of neck motoneurons in the adult cat give rise to unusual processes that, at a light microscopic level, resemble axons (Rose, P.K. & Odlozinski, M., J. Comp. Neurol., 1998, 390, 392). The goal of the present experiments was to characterize these unusual processes using well-established ultrastructural and molecular criteria that differentiate dendrites and axons. These processes were immunoreactive for growth-associated protein-43 (GAP-43), a protein that is normally confined to axons. In contrast, immunoreactivity for a protein that is widely used as a marker for dendrites, microtubule-associated protein (MAP)-2a/b, could not be detected in the unusual distal arborizations. At the electron microscopic level, unusual distal processes contained dense collections of neurofilaments and were frequently myelinated. These molecular and structural characteristics are typical of axons and suggest that the polarity of adult neurons in the mammalian nervous system can be disrupted by axotomy. If this transformation in neuronal polarity is common to other types of neurons, axon-like processes emerging from distal dendrites may represent a mechanism for replacing connections lost due to injury. Alternatively, the connections formed by these axons may be aberrant and therefore maladaptive. IS - 6 JF - The European journal of neuroscience SN - 0953-816X AD - CIHR Group in Sensory-Motor Systems, Department of Physiology, Queen's University, Kingston, Ont., Canada. ken@biomed.queensu.ca EP - 1176 TI - Emergence of axons from distal dendrites of adult mammalian neurons following a permanent axotomy. VL - 13 SP - 1166 KW - axon KW - dendrite KW - neuron KW - polarity N1 - using cats, axotomy makes axons grow from dista dendrites of motor neurones. AU - Rose, PK AU - MacDermid, V AU - Joshi, M AU - Neuber-Hess, M PY - 2001/03// UR - http://view.ncbi.nlm.nih.gov/pubmed/11285014 ER -