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NMDA receptors and activity-dependent tuning of the receptive fields of spinal cord neurons

Item Type:Article
Title:NMDA receptors and activity-dependent tuning of the receptive fields of spinal cord neurons
Creators Name:Lewin, G.R. and Mckintosh, E. and McMahon, S.B.
Abstract:After peripheral nerve section, sensory neurons regenerate but do not regain their original topographical position in the skin. Here we report that in the early stages of sciatic nerve regeneration, the cutaneous receptive fields (RFs) of dorsal horn neurons are larger than normal, reflecting the disorganized topography of the regenerated afferents. When nerve regeneration is complete, small contiguous RFs emerge, indicating a central compensation for the disrupted peripheral somatotopy. If the NMDA receptor antagonist MK801 is given during regeneration, RFs do not show this reorganization, but remain large and diffuse. We suggest that the coincident activity of afferents, newly innervating adjacent or overlapping cutaneous territory, acts through postsynaptic NMDA receptors to strengthen the central effectiveness of these inputs at the expense of other non-adjacent and non-coincidently activated inputs. In this way, dorsal horn neurons may attain and retain restricted RFs in the face of a spatially dispersed afferent input.
Keywords:Dizocilpine Maleate, Nerve Regeneration, Afferent Neurons, N-Methyl-D-Aspartate Receptors, Sciatic Nerve, Sensory Receptor Cells, Skin, Spinal Cord, Animals, Rats
Publisher:Nature Publishing Group
Page Range:482-485
Date:9 June 1994
Official Publication:https://doi.org/10.1038/369482a0
PubMed:View item in PubMed

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