| Responses of human mechanoreceptive afferents to embossed dot arrays scanned across fingerpad skin. | |
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MedLine Citation:
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PMID: 1545242 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The spatial resolving capacities of the four classes of mechanoreceptive afferents innervating human fingerpad skin were investigated to determine which class sets the limit of tactile spatial resolution for scanning stimuli. The stimulus consisted of an array of embossed dots (0.7 mm diameter, 0.5 mm high) arranged in a tetragonal pattern with dot spacing decreasing linearly from 6.4 mm at one end of the array to 0.87 mm at the other. The pattern was wrapped around a drum and repeatedly scanned across the receptive field of single afferents by continuously rotating the drum. Responses to many closely spaced scans were obtained by imposing a lateral shift of the pattern between each revolution. Impulses were recorded microneurographically. Responses were plotted in raster form to produce a neural image of the pattern. Responses of rapidly and slowly adapting type I (FAI and SAI) afferents resolved dots down to a spacing of about 1.5 mm. Responses of type II (FAII and SAII) afferents resolved dots down to a spacing of about 3.5 mm. Variation in scanning speed (range, 20-90 mm/sec) and contact force (range, 0.4-1.0 N) had minimal effects on spatial resolution of all afferents. The response clusters associated with individual widely spaced dots were used to investigate receptive field structure. FAI and SAI fields (mean areas, 6.1 and 4.8 mm2, respectively) each contained several zones of maximal sensitivity. FAI fields had five to eight such zones, whereas SAI fields had three to five such zones. As dot spacing decreased, neighboring dots interacted to affect the responses associated with the individual zones within a field. Initially, one or more zones were deactivated, effectively reducing receptive field size and allowing representation of finer spatial detail than would be predicted from the overall area of the receptive field. At very close dot spacings responses were only obtained when more than one sensitive zone within a field were simultaneously activated by different dots. |
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Authors:
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J R Phillips; R S Johansson; K O Johnson |
Publication Detail:
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Type: Comparative Study; Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
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Title: The Journal of neuroscience : the official journal of the Society for Neuroscience Volume: 12 ISSN: 0270-6474 ISO Abbreviation: J. Neurosci. Publication Date: 1992 Mar |
Date Detail:
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Created Date: 1992-04-16 Completed Date: 1992-04-16 Revised Date: 2009-09-29 |
Medline Journal Info:
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Nlm Unique ID: 8102140 Medline TA: J Neurosci Country: UNITED STATES |
Other Details:
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Languages: eng Pagination: 827-39 Citation Subset: IM; S |
Affiliation:
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University Laboratory of Physiology, Oxford, United Kingdom. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Adult Electrophysiology Female Fingers / innervation* Humans Male Mechanoreceptors / physiology* Neurons, Afferent / physiology* Physical Stimulation Skin / innervation* Space Perception / physiology* Touch / physiology* |
| Grant Support | |
ID/Acronym/Agency:
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NS18787/NS/NINDS NIH HHS; //Wellcome Trust |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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