Visual Neuroscience



Ganglion cells of a short-wavelength-sensitive cone pathway in New World monkeys: Morphology and physiology


LUIZ CARLOS L.  SILVEIRA a1c1, BARRY B.  LEE a2, ELIZABETH S.  YAMADA a1, JAN  KREMERS a3, DAVID M.  HUNT a4, PAUL R.  MARTIN a5 and FRANCINALDO L.  GOMES a1
a1 Departamento de Fisiologia, Universidade Federal do Pará, 66075-900 Belém, Pará, Brazil
a2 Department of Neurobiology, Max-Planck Institute for Biophysical Chemistry, D-37077 Göttingen, Germany
a3 Department of Experimental Ophthalmology, University of Tübingen Eye Hospital, Tübingen, Germany
a4 Department of Molecular Genetics, Institute of Ophthalmology, University College London, England, U.K.
a5 Department of Physiology F13, University of Sydney, Australia

Abstract

We have studied the morphology and physiology of retinal ganglion cells of a short-wavelength-sensitive cone (SWS-cone) pathway in dichromatic and trichromatic New World anthropoids, the capuchin monkey (Cebus apella) and tufted-ear marmoset (Callithrix jacchus). In Old World anthropoids, in which males and females are both trichromats, blue-ON/yellow-OFF retinal ganglion cells have excitatory SWS-cone and inhibitory middle- and long-wavelength-sensitive (MWS- and LWS-) cone inputs, and have been anatomically identified as small-field bistratified ganglion cells (SB-cells) (Dacey & Lee, 1994). Among retinal ganglion cells of New World monkeys, we find SB-cells which have very similar morphology to such cells in macaque and human; for example, the inner dendritic tree is larger and denser than the outer dendritic tree. We also find blue-on retinal ganglion cells of the capuchin to have physiological responses strongly resembling such cells of the macaque monkey retina; for example, responses were more sustained, with a gentler low frequency roll-off than MC-cells, and no evidence of contrast gain control. There was no difference between dichromatic and trichromatic individuals. The results support the view that SWS-cone pathways are similarly organized in New and Old World primates, consistent with the hypothesis that these pathways form a phylogenetically ancient color system.

(Received December 18 1997)
(Accepted August 31 1998)


Key Words: Small-field bistratified ganglion cells; Blue-on ganglion cells; SWS-cones; Cebus apella; Callithrix jacchus.

Correspondence:
c1 Correspondence and reprint requests to: Luiz Carlos de Lima Silveira, Universidade Federal do Pará, Centro de Ciências Biológicas, Departamento de Fisiologia, 66075-900 Belém, Pará, Brazil.