Linked Life Data

9425177

Source:http://linkedlifedata.com/resource/pubmed/id/9425177

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1998-2-18
pubmed:abstractText
A normal environment often contains many objects of interest that compete to attract our gaze. Nevertheless, instead of initiating a flurry of conflicting signals, central populations of oculomotor neurons always seem to agree on the destination of the next saccade. How is such a consensus achieved? In a unit recording and microstimulation study on trained monkeys, we sought to elucidate the mechanism through which saccade-related cells in the frontal eye fields (FEF) avoid issuing competing commands. Presaccadic neuronal activity was recorded in one FEF while stimulating the contralateral FEF with low-intensity currents that evoked saccades. When an eye-movement cell was isolated, we determined: the movement field of the cell, the cell's response to contralateral FEF microstimulation, the cell's response when the evoked saccade was in the preferred direction of the cell (using the collision technique to deviate appropriately the evoked saccade vector), and the cell's response to a stimulation applied during a saccade in the cell's preferred direction, to reveal a possible inhibitory effect. Complete results were obtained for 71 stimulation-recording pairs of FEF sites. The unit responses observed were distributed as follows: 35% of the cells were unaffected, 37% were inhibited, and 20% excited by contralateral stimulation. These response types depended on the site of contralateral stimulation and did not vary when saccades were redirected by collision. This invariant excitation or inhibition of cells, seemingly due to hardwired connections, depended on the angular difference between their preferred vector and the vector represented by the cells stimulated. By contrast, 8% of the cells were either activated or inhibited depending on the vector of the saccade actually evoked by collision. These results suggest that the consensus between cells of oculomotor structures at the time of saccade initiation is implemented by functional connections such that the cells that command similar movements mutually excite each other while silencing those that would produce conflicting movements. Such a rule would be an effective implementation of a winner-take-all mechanism well suited to prevent conflicts.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0022-3077
pubmed:author
pubmed:issnType
Print
pubmed:volume
79
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
64-72
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Interaction of the two frontal eye fields before saccade onset.
pubmed:affiliation
Department of Neurobiology and Brain Research Institute, UCLA School of Medicine, Los Angeles, California 90095-1763, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.