Document Detail


Active signaling of leg loading and unloading in the cockroach.
MedLine Citation:
PMID:  10085370     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The ability to detect changes in load is important for effective use of a leg in posture and locomotion. While a number of limb receptors have been shown to encode increases in load, few afferents have been demonstrated to signal leg unloading, which occurs cyclically during walking and is indicative of slipping or perturbations. We applied mechanical forces to the cockroach leg at controlled rates and recorded activities of the tibial group of campaniform sensilla, mechanoreceptors that encode forces through the strains they produce in the exoskeleton. Discrete responses were elicited from the group to decreasing as well as increasing levels of leg loading. Discharges of individual afferents depended on the direction of force application, and unit responses were correlated morphologically with the orientation of the receptor's cuticular cap. No units responded bidirectionally. Although discharges to decreasing levels of load were phasic, we found that these bursts could effectively encode the rate of force decreases. These discharges may be important in indicating leg unloading in the step cycle during walking and could rapidly signal force decreases during perturbations or loss of ground support.
Authors:
A L Ridgel; S F Frazier; R A Dicaprio; S N Zill
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  Journal of neurophysiology     Volume:  81     ISSN:  0022-3077     ISO Abbreviation:  J. Neurophysiol.     Publication Date:  1999 Mar 
Date Detail:
Created Date:  1999-05-06     Completed Date:  1999-05-06     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0375404     Medline TA:  J Neurophysiol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1432-7     Citation Subset:  IM; S    
Affiliation:
Department of Anatomy, Cell and Neurobiology, Marshall University School of Medicine, Huntington, West Virginia 25704, USA.
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MeSH Terms
Descriptor/Qualifier:
Afferent Pathways / physiology
Animals
Locomotion / physiology*
Mechanoreceptors / physiology
Periplaneta
Posture / physiology*
Sense Organs / physiology*
Signal Transduction / physiology*
Tibia / physiology*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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