Show Reference: "Comparison of Cortico-Cortical and Cortico-Collicular Signals for the Generation of Saccadic Eye Movements"

Comparison of Cortico-Cortical and Cortico-Collicular Signals for the Generation of Saccadic Eye Movements Journal of Neurophysiology, Vol. 87, No. 2. (February 2002), pp. 845-858 by Stefano Ferraina, Martin Paré, Robert H. Wurtz
    abstract = {Many neurons in the frontal eye field ({FEF}) and lateral intraparietal ({LIP}) areas of cerebral cortex are active during the visual-motor events preceding the initiation of saccadic eye movements: they respond to visual targets, increase their activity before saccades, and maintain their activity during intervening delay periods. Previous experiments have shown that the output neurons from both {LIP} and {FEF} convey the full range of these activities to the superior colliculus ({SC}) in the brain stem. These areas of cerebral cortex also have strong interconnections, but what signals they convey remains unknown. To determine what these cortico-cortical signals are, we identified the {LIP} neurons that project to {FEF} by antidromic activation, and we studied their activity during a delayed-saccade task. We then compared these cortico-cortical signals to those sent subcortically by also identifying the {LIP} neurons that project to the intermediate layers of the {SC}. Of 329 {FEF} projection neurons and 120 {SC} projection neurons, none were co-activated by both {FEF} and {SC} stimulation. {FEF} projection neurons were encountered more superficially in {LIP} than {SC} projection neurons, which is consistent with the anatomical projection of many cortical layer {III} neurons to other cortical areas and of layer V neurons to subcortical structures. The estimated conduction velocities of {FEF} projection neurons (16.7 m/s) were significantly slower that those of {SC} projection neurons (21.7 m/s), indicating that {FEF} projection neurons have smaller axons. We identified three main differences in the discharge properties of {FEF} and {SC} projection neurons: only 44\% of the {FEF} projection neurons changed their activity during the delayed-saccade task compared with 69\% of the {SC} projection neurons; only 17\% of the task-related {FEF} projection neurons showed saccadic activity, whereas 42\% of the {SC} projection neurons showed such increases; 78\% of the {FEF} projection neurons had a visual response but no saccadic activity, whereas only 55\% of the {SC} projection neurons had similar activity. The {FEF} and {SC} projection neurons had three similarities: both had visual, delay, and saccadic activity, both had stronger delay and saccadic activity with visually guided than with memory-guided saccades, and both had broadly tuned responses for disparity stimuli, suggesting that their visual receptive fields have a three-dimensional configuration. These observations indicate that the activity carried between parietal and frontal cortical areas conveys a spectrum of signals but that the preponderance of activity conveyed might be more closely related to earlier visual processing than to the later saccadic stages that are directed to the {SC}.},
    author = {Ferraina, Stefano and Par\'{e}, Martin and Wurtz, Robert H.},
    citeulike-article-id = {12782384},
    citeulike-linkout-0 = {},
    citeulike-linkout-1 = {},
    issn = {0022-3077},
    journal = {Journal of Neurophysiology},
    keywords = {biology, cortex, sc, sc-input},
    month = feb,
    number = {2},
    pages = {845--858},
    pmid = {11826051},
    posted-at = {2014-09-25 16:09:25},
    priority = {2},
    title = {Comparison of {Cortico-Cortical} and {Cortico-Collicular} Signals for the Generation of Saccadic Eye Movements},
    url = {},
    volume = {87},
    year = {2002}

See the CiteULike entry for more info, PDF links, BibTex etc.

FEF and LIP stimulation elicits saccadic eye and head movements.

Lateral intraparietal area (LIP) projects to intermediate layers of SC.

the frontal eye fields (fef) project to the SC and to the brainstem directly.