File Download

There are no files associated with this item.

  Links for fulltext
     (May Require Subscription)
Supplementary

Article: Dynamics and directional sensitivity of neck muscle spindle responses to head rotation

TitleDynamics and directional sensitivity of neck muscle spindle responses to head rotation
Authors
Issue Date1987
Citation
Journal Of Neurophysiology, 1987, v. 57 n. 6, p. 1716-1729 How to Cite?
AbstractWith the use of floating electrodes we recorded from the C2 dorsal root ganglion of decerebrate cats using sinusoidal and trapezoidal head rotation. Fifty-one spontaneously firing afferents were identified as muscle spindle endings. Some were identified by their excitatory response to injection of succinylcholine, others by the similarity of their behavior to that of endings excited by the drug. Because afferent input to the ganglion was restricted by sectioning most nerve trunks, most spindle endings were presumably located in ventral and ventrolateral perivertebral muscles. The firing of each spindle afferent was modulated most effectively by tilting the head in a specific direction; this direction was termed its response vector. Responses to sine waves and trapezoids were then studied with stimuli oriented as closely as possible to the vertical plane of this vector. Most spindle afferents could be classified in one of two categories. Those with high gain, pronounced nonlinearity, and high dynamic index were called type A. Those classified as type B had low gain, a fairly linear response, and low dynamic index. In response to small (0.5°) stimuli, type A endings had phase leads of ~40° at frequencies of sinusoidal stimulation of 0.02-0.1 Hz, increasing to ~80° at 4 Hz; with larger (2.5°) stimuli, phase was advanced by an additional 10-20° at all frequencies. Phase of type B responses was less advanced than that of type A responses. Gain slopes of the two types of endings were similar. Bode plots of spindle afferents strongly resembled those of upper cervical neurons whose activity is modulated by head rotation. Each spindle afferent had a response vector whose direction remained stable with time, different frequencies of stimulation, and different stimulus amplitudes. The distribution of response vectors covered ~270°, with a gap near nose down pitch. Changing initial head position usually had little effect on the direction of an afferent's response vector or on response dynamics. However, stimulation far from the best plane could transform a type A into a type B response. This raises the possibility that type B receptors could be type A receptors best stimulated by yaw and with only low sensitivity to stimulation in vertical planes. Type A receptors have all the properties of spindle primaries. The identification of type B receptors remains uncertain, because they may include secondary afferents as well as primaries stimulated far from their best three-dimensional vector. The properties of neck spindle endings support the suggestion that they contribute important afferent input to the cervicocollic and tonic neck reflexes.
Persistent Identifierhttp://hdl.handle.net/10722/171511
ISSN
2015 Impact Factor: 2.653
2015 SCImago Journal Rankings: 2.230
ISI Accession Number ID

 

DC FieldValueLanguage
dc.contributor.authorChan, YSen_US
dc.contributor.authorKasper, Jen_US
dc.contributor.authorWilson, VJen_US
dc.date.accessioned2012-10-30T06:15:29Z-
dc.date.available2012-10-30T06:15:29Z-
dc.date.issued1987en_US
dc.identifier.citationJournal Of Neurophysiology, 1987, v. 57 n. 6, p. 1716-1729en_US
dc.identifier.issn0022-3077en_US
dc.identifier.urihttp://hdl.handle.net/10722/171511-
dc.description.abstractWith the use of floating electrodes we recorded from the C2 dorsal root ganglion of decerebrate cats using sinusoidal and trapezoidal head rotation. Fifty-one spontaneously firing afferents were identified as muscle spindle endings. Some were identified by their excitatory response to injection of succinylcholine, others by the similarity of their behavior to that of endings excited by the drug. Because afferent input to the ganglion was restricted by sectioning most nerve trunks, most spindle endings were presumably located in ventral and ventrolateral perivertebral muscles. The firing of each spindle afferent was modulated most effectively by tilting the head in a specific direction; this direction was termed its response vector. Responses to sine waves and trapezoids were then studied with stimuli oriented as closely as possible to the vertical plane of this vector. Most spindle afferents could be classified in one of two categories. Those with high gain, pronounced nonlinearity, and high dynamic index were called type A. Those classified as type B had low gain, a fairly linear response, and low dynamic index. In response to small (0.5°) stimuli, type A endings had phase leads of ~40° at frequencies of sinusoidal stimulation of 0.02-0.1 Hz, increasing to ~80° at 4 Hz; with larger (2.5°) stimuli, phase was advanced by an additional 10-20° at all frequencies. Phase of type B responses was less advanced than that of type A responses. Gain slopes of the two types of endings were similar. Bode plots of spindle afferents strongly resembled those of upper cervical neurons whose activity is modulated by head rotation. Each spindle afferent had a response vector whose direction remained stable with time, different frequencies of stimulation, and different stimulus amplitudes. The distribution of response vectors covered ~270°, with a gap near nose down pitch. Changing initial head position usually had little effect on the direction of an afferent's response vector or on response dynamics. However, stimulation far from the best plane could transform a type A into a type B response. This raises the possibility that type B receptors could be type A receptors best stimulated by yaw and with only low sensitivity to stimulation in vertical planes. Type A receptors have all the properties of spindle primaries. The identification of type B receptors remains uncertain, because they may include secondary afferents as well as primaries stimulated far from their best three-dimensional vector. The properties of neck spindle endings support the suggestion that they contribute important afferent input to the cervicocollic and tonic neck reflexes.en_US
dc.languageengen_US
dc.relation.ispartofJournal of Neurophysiologyen_US
dc.subject.meshAnimalsen_US
dc.subject.meshBiophysical Phenomenaen_US
dc.subject.meshBiophysicsen_US
dc.subject.meshCatsen_US
dc.subject.meshDecerebrate State - Physiopathologyen_US
dc.subject.meshElectric Stimulationen_US
dc.subject.meshGanglia, Spinal - Physiologyen_US
dc.subject.meshHeaden_US
dc.subject.meshMuscle Spindles - Physiologyen_US
dc.subject.meshMuscles - Innervationen_US
dc.subject.meshNeck Muscles - Innervationen_US
dc.subject.meshReflex, Stretchen_US
dc.subject.meshRotationen_US
dc.titleDynamics and directional sensitivity of neck muscle spindle responses to head rotationen_US
dc.typeArticleen_US
dc.identifier.emailChan, YS:yschan@hkucc.hku.hken_US
dc.identifier.authorityChan, YS=rp00318en_US
dc.description.naturelink_to_subscribed_fulltexten_US
dc.identifier.pmid2955083-
dc.identifier.scopuseid_2-s2.0-0023255486en_US
dc.identifier.volume57en_US
dc.identifier.issue6en_US
dc.identifier.spage1716en_US
dc.identifier.epage1729en_US
dc.identifier.isiWOS:A1987H699900006-
dc.publisher.placeUnited Statesen_US
dc.identifier.scopusauthoridChan, YS=7403676627en_US
dc.identifier.scopusauthoridKasper, J=7102279144en_US
dc.identifier.scopusauthoridWilson, VJ=7202995605en_US

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats