Display Settings:

Format

Send to:

Choose Destination
We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
    Vis Neurosci. 1994 May-Jun;11(3):579-600.

    Divergent feedback connections from areas V4 and TEO in the macaque.

    Source

    Department of Neurology, University of Iowa, Iowa City.

    Abstract

    Extrastriate areas TEO and V4 have been associated with form and color vision. Area V4 has also been suggested to participate in processes concerned with attention, stimulus salience, and perceptual learning. In a continuing effort to elucidate the connectional interactions and microcircuitry of these areas, we describe in this report the pattern of feedback connections from TEO and V4. Connections were demonstrated by injections of the high-resolution anterograde tracers PHA-L or biocytin and further analyzed by reconstruction of 25 individual axons through serial sections. This analysis yielded several new results: (1) Both areas TEO and V4 have widespread feedback connections (defined by their preferential termination in layer 1 and avoidance of layer 4). From TEO, there are dense projections to area V4 and moderate ones to V2 and V1. From V4, there are dense projections to V2 and moderate ones to V3 and V1. (2) Terminal fields span large territories in area V1, up to 6.0 mm in the case of axons originating from TEO; up to 5.0 mm in the case of axons originating from V4. In V2, fields tend to be smaller, between 3.0-5.0 mm. (3) Many axons from TEO and some from V4 have terminations in both areas V1 and V2. (4) Because individual terminal clusters and segments are often larger than cytochrome oxidase compartments, especially in V1, we suggest they may not be correlated with this compartmental organization. These results are consistent with the hypothesis that feedback connections may contribute to processes other than perceptual discrimination.

    PMID:
    8038130
    [PubMed - indexed for MEDLINE]

    LinkOut - more resources

    Other Literature Sources

    Molecular Biology Databases

      Supplemental Content

      Save items

      Recent activity

      Your browsing activity is empty.

      Activity recording is turned off.

      Turn recording back on

      See more...
      Write to the Help Desk