Linked Life Data

8338382

Source:http://linkedlifedata.com/resource/pubmed/id/8338382

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2-3
pubmed:dateCreated
1993-8-23
pubmed:abstractText
In rabbits and cats vestibulo-ocular reflex (VOR) and vestibulo-ocular reflex (VCR) were tested in frontal and sagittal planes. The VOR evoked by pitching the animals in side down position showed asymmetric responses with peak eye velocity higher in upward direction than in downward one. This asymmetry was abolished when pitching the animal in upright position. This indicate that the otolithic coactivation, occurring in upright position, symmetrizes canal-induced vertical responses. Vestibulo-ocular reflex evoked by rolling the animals was also symmetric, no matter the animal position was. The electromyographic response of neck muscles to sagittal VCR showed an asymmetric behaviour as far as the timing of extensor and flexor activation was concerning. In fact, the increase of extensor muscle activity was steeper than the decrease and the activation peak was more leading than the inhibition peak. The flexor muscles showed an opposite behaviour. This flexion-extension asymmetry was present either with or without otolithic coactivation. On the contrary, the EMG responses to frontal VCR were much more symmetric. It can be suggested that the upward preponderance is present in the sagittal vestibular circuitry to enhance the upward VCR against a gravity load which opposes head stability during downward head displacements. On the contrary, at level of the eye, in which the gravity does not oppose the responses, the canal-induced vertical asymmetry is cancelled by the otolithic coactivation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0003-9829
pubmed:author
pubmed:issnType
Print
pubmed:volume
131
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
105-15
pubmed:dateRevised
2009-10-5
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Asymmetries in ocular and cervical responses to sagittal vestibular stimulations.
pubmed:affiliation
Istituto di Fisiologia Umana, Università di Perugia, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't