|
Dacey, Dennis, Ph.D.
Professor
dmd@u.washington.edu
I-419A
543-3315
It is now well accepted that the vertebrate retina contains on the order of 50-60
distinct neural cell types. Why does the retina, situated at the earliest stage of the visual process, require so many cell
types? One hypothesis is that the photoreceptor responses to light are channelled into a number of parallel signal pathways that
separately encode various aspects of a visual image and play different roles in visual perception. In the retina each of
these visual pathways would be composed of a set of interneurons linked to an output neuron, the ganglion cell, whose axon projects to
a target in the brain. To test this hypothesis we are attempting to identify each of the retinal ganglion cell types and
their associated interneurons. Work in the lab has recently focused on the retina of the human and macaque monkey. In
the primate we know that some ganglion cell types receive excitatory input from red, green, or blue cone photoreceptors and therefore
show color selective light responses; other ganglion cell types are excited equally by all of the cone types and are non-color
selective. The neural organization that gives rise to these distinct signal pathways is unknown. To approach the
problem we are using intracellular recording and staining in in vitro preparation of the macaque retina to identify the color-coding
light responses of morphologically identified ganglion cell types.
References
Dacey, D.M., and Brace, S.
(1992) A coupled network for parasol but not midget ganglion cells in the primate retina. Visual Neuroscience 9: 279-290.
Dacey, D.M., and Petersen, M. (1992) Dendritic field size and morphology of midget parasol ganglion cells of the human
retina. Proc. Natl. Acad Sci. USA. 89: 9666-9670.
Milam, A.H., Dacey, D.M., and Dizhoor, A.M. (1993)
Recovering immunoreactivity in mammalian cone bipolar cells. Visual Neuroscience 10: 1-12.
Dacey, D.M. (1993)
Morphology of a small-field bistratified ganglion cell type in the macaque and human retina. Visual Neuroscience 10:
1081-1098.
Dacey, D.M. (1993) The mosaic of midget ganglion cells in the human retina. The Journal of
Neuroscience 13:5334-5355.
Dacey, D.M., and Lee, B.B. (1994) The blue-ON opponent pathway in primate retina originates
from a distinct bistratified ganglion cell type. Nature 367: 731-735.
Dacey DM, Peterson BB, Robinson FR, Gamlin PD (2003)
Fireworks in the primate retina: in vitro photodynamics reveals diverse LGN-projecting ganglion cell types. Neuron 37(1):15-27
Lee
BB, Dacey DM, Smith VC, Pokorny J (2003) Dynamics of sensitivity regulation in primate outer retina: the horizontal cell network.
Journal of Vision 3:513-26
Dacey DM, Packer OS (2003) Colour coding in the primate retina: diverse cell types and cone-specific
circuitry. Current Opinion in Neurobiology 13: 421-427.
Diller LC, Packer OS, Verweij J, McMahon MJ, Williams DR, Dacey DM (2004)
L- and M-cone contributions to the midget and parasol ganglion cell receptive fields of macaque monkey retina. Journal of
Neuroscience 24(5):1079-1088
McMahon MJ, Packer OS, Dacey DM (2004) The classical receptive field surround of primate parasol
ganglion cells is mediated primarily by a non-GABAergic pathway. Journal of Neuroscience, 24(15):3736-3745.
Dacey DM, Liao H-W,
Peterson BB, McDougal DH, Robinson FR, Smith VC, Pokorny J, Yau K-W, Gamlin PD (2005) Melanopsin-expressing ganglion cells in primate
retina project to the LGN and signal both color and irradiance. Nature 433:749-754.
Packer, OS, Dacey DM (2005) Synergistic
center-surround receptive field model of monkey H1 horizontal cells. Journal of Vision, 5(11): 1038-1054.
Gamlin PD, McDougal DH, Smith
VC, Dacey DM, Pokorny J, Yau K-W. Human and macaque pupil responses driven by intrinsically photoreceptive retinal ganglion cells.
Submitted.
|
