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0:00
My name is Russell Foster.
I'm Professor of Circadian
Neuroscience,
Head of the Nuffield Laboratory
of Ophthalmology,
and Director
of the Sleep and Circadian
Neuroscience Institute
here in Oxford.
What I'd like to consider
in this presentation
is this new photoreceptor system
that's been recently identified
within the eye and so the title is,
"Defining the Third Photoreceptor
System within the Eye."
0:23
Well, I thought I'd cover
in this presentation
are the following topics.
I'd like to consider the diversity
of vertebrate photoreceptors
in place,
the discovery of this new
photoreceptor system within the eye
and within the broader context of
irradiance or brightness detection
of the vertebrate
photoreceptor systems,
then give
a little bit of introduction
into the circadian system
and the early work
with retinal degenerate mice,
and how that led really
to the development
of rodless, coneless mouse,
the rd cl mouse,
and the discovery of these
melanopsin-based
photosensitive
retinal ganglion cells,
and then consider
how this work in rodents
really relates
to clinical ophthalmology
and the human studies
that are currently being undertaken
and then try and follow
with a few summary comments
right at the end.
So let's kick off
with the diversity
of vertebrate photoreceptors.
1:18
If we look at the vertebrates
as a group,
they're about 50 families or more,
and what's very striking is that
the vertebrates can be divided
into two groups
based upon the sort of
photoreceptor systems they use.
So if we consider the birds,
the reptiles, amphibians, fish
and indeed the agnathans,
the lampreys and hagfish,
they have a huge diversity
of photoreceptors.
So let's briefly look at
the diversity of photoreceptors
in these non-mammalian vertebrates.
