Morphology and physiology of primate M- and P-cells.

摘要: Abstract Catarrhines and platyrrhines, the so-called Old- New-World anthropoids, have different cone photopigments. Postreceptoral mechanisms must coevolved with receptors to provide trichromatic color vision, so it is important compare postreceptoral processes in these two primate groups, both from anatomical physiological perspectives. The morphology of ganglion cells has been studied retina catarrhines such as diurnal Macaca , well platyrrhines diurnal, di- or Cebus nocturnal, monochromatic Aotus . Diurnal trichromats, cell classes very similar those found catarrhines: M (parasol), P (midget), small-field bistratified, several wide-field cells. In fovea all P-cell dendritic trees contact single midget bipolars, which cones. far fewer cones than species, but M- P-cells are primates although larger size. As majority bipolar cells, central 2 mm eccentricity, receive input a sizes their axon terminals match fields same region. visual responses retinal species using single-unit electrophysiological recordings. Recordings showed that they properties macaque, except mono- dichromatic animals lack opponency. Whatever original role was, likely evolved prior divergence platyrrhines. systems thus appear be strongly conserved various species. reasons for this may lie roles achromatic chromatic vision.