Artificial Organs,
Journal Year:
2024,
Volume and Issue:
48(11), P. 1223 - 1250
Published: July 18, 2024
Retinal
prostheses
offer
hope
for
individuals
with
degenerative
retinal
diseases
by
stimulating
the
remaining
cells
to
partially
restore
their
vision.
This
review
delves
into
current
advancements
in
prosthesis
technology,
a
special
emphasis
on
pivotal
role
that
image
processing
and
machine
learning
techniques
play
this
evolution.
Frontiers in Cellular Neuroscience,
Journal Year:
2025,
Volume and Issue:
19
Published: March 4, 2025
In
the
outer
vertebrate
retina,
visual
signal
is
separated
into
intensity
and
wavelength
information.
birds,
seven
types
of
photoreceptors
(one
rod,
four
single
cones,
two
members
double
cone)
mediate
signals
to
>20
second-order
neurons,
bipolar
cells
horizontal
cells.
Horizontal
contribute
color
contrast
processing
by
providing
feedback
feedforward
fish,
reptiles,
amphibians
they
either
encode
or
show
color-opponent
responses.
Yet,
for
bird
number
cell
not
fully
resolved
even
more
importantly,
synapses
between
have
never
been
quantified
any
species.
With
a
combination
light
microscopy
serial
EM
reconstructions,
we
found
different
in
distantly
related
species,
domestic
chicken
European
robin.
agreement
with
some
earlier
studies,
confirmed
highly
abundant
(H1,
H2)
rare
(H3,
H4),
which
H1
an
axon-bearing
cell,
whereas
H2-H4
are
axonless.
made
chemical
one
type
interplexiform
amacrine
at
their
soma.
Dendritic
contacts
H1-H4
were
type-specific
similar
turtle
confirms
high
degree
evolutionary
conservation
retina.
Our
data
further
suggests
that
potentially
H2
may
intensity,
H3
H4
represent
opponent
birds’
superb
and/or
acuity
vision.
PLoS Biology,
Journal Year:
2024,
Volume and Issue:
22(1), P. e3002422 - e3002422
Published: Jan. 22, 2024
When
vertebrates
first
conquered
the
land,
they
encountered
a
visual
world
that
was
radically
distinct
from
of
their
aquatic
ancestors.
Fish
exploit
strong
wavelength-dependent
interactions
light
with
water
by
differentially
feeding
signals
up
to
5
spectral
photoreceptor
types
into
behavioural
programmes.
However,
above
same
rules
do
not
apply,
and
this
called
for
an
update
circuit
strategies.
Early
tetrapods
soon
evolved
double
cone,
still
poorly
understood
pair
new
photoreceptors
brought
“ancestral
terrestrial”
complement
7.
Subsequent
nonmammalian
lineages
adapted
highly
parallelised
retinal
input
strategy
diverse
ecologies.
By
contrast,
mammals
shed
most
ancestral
converged
on
is
exceptionally
general.
In
eutherian
including
in
humans,
parallelisation
emerges
gradually
as
signal
traverses
layers
retina
brain.
Communications Biology,
Journal Year:
2024,
Volume and Issue:
7(1)
Published: Aug. 14, 2024
Abstract
In
most
avian
retinas,
double
cones
(consisting
of
a
principal
and
accessory
member)
outnumber
other
photoreceptor
types
have
been
associated
with
various
functions,
such
as
encoding
luminance,
sensing
polarized
light,
magnetoreception.
However,
their
down-stream
circuitry
is
poorly
understood,
particularly
across
bird
species.
Analysing
species
differences
important
to
understand
changes
in
driven
by
ecological
adaptations.
We
compare
the
ultrastructure
postsynaptic
bipolar
cells
between
night-migratory
European
robin
non-migratory
chicken.
discover
four
previously
unidentified
cell
retina,
including
midget-like
mainly
connected
one
member.
A
downstream
ganglion
reveals
complete
circuit
similar
peripheral
primate
retina.
Additionally,
we
identify
selective
transmitting
information
from
specific
subset
members.
Our
data
highlight
species-specific
cone
connectivity,
potentially
reflecting
Scientific Reports,
Journal Year:
2025,
Volume and Issue:
15(1)
Published: March 6, 2025
Retinal
cone
photoreceptors
are
specialized
neurons
that
capture
light
to
begin
the
process
of
daylight
vision.
They
occur
as
individual
cells
(i.e.,
single
cones),
or
combinations
structurally
linked
cells,
such
double
and
triple
cones
found
in
retinas
non-eutherian
vertebrates.
These
different
morphological
types
form
mosaics
varying
regularity,
with
patterned
nearly
perfect
lattices
many
bony
fishes
(teleosts)
some
geckos.
Although
were
first
reported
over
150
years
ago,
how
they
whether
from
coalescing
cones,
progenitors)
remains
uncertain.
In
turn,
there
is
a
general
vertebrate
sequence
appearance
unknown.
Here,
developing
seven
species
teleosts
examined
revealing
only
arranged
hexagonal-like
mosaics,
present
at
earliest
stages
photoreceptor
differentiation.
Double
arose
formation
multi-cone
type
(such
square
mosaic,
where
each
surrounded
by
four
cones)
followed
dynamics
depending
on
was
altricial
precocial.
Single
therefore
primordial
which
all
preceded
other
mosaic
patterns.
Based
observations
transitional
retinas,
we
propose
model
for
transformation
hexagonal
square.
The
those
land
vertebrates
constitute
an
example
convergent
evolution
achieve
elliptical
waveguide
structure,
likely
improved
spatio-temporal
resolution.
PLoS Biology,
Journal Year:
2025,
Volume and Issue:
23(5), P. e3003157 - e3003157
Published: May 7, 2025
Vertebrate
photoreceptors
have
been
studied
for
well
over
a
century,
but
fixed
nomenclature
referring
to
orthologous
cell
types
across
diverse
species
has
lacking.
Instead,
variably—and
often
confusingly—named
according
morphology,
presence/absence
of
‘rhodopsin’,
spectral
sensitivity,
chromophore
usage,
and/or
the
gene
family
opsin(s)
they
express.
Here,
we
propose
unified
vertebrate
rods
and
cones
that
aligns
with
naming
systems
other
retinal
classes
is
based
on
photoreceptor
type’s
putative
evolutionary
history.
This
classification
informed
by
functional,
anatomical,
developmental,
molecular
identities
neuron
as
whole,
including
expression
deeply
conserved
transcription
factors
required
development.
The
proposed
names
will
be
applicable
all
vertebrates
indicative
widest
possible
range
properties,
their
postsynaptic
wiring,
hence
allude
common
species-specific
roles
in
vision.
Furthermore,
system
open-ended
accommodate
future
discovery
as-yet
unknown
types.
Nature Communications,
Journal Year:
2023,
Volume and Issue:
14(1)
Published: Aug. 31, 2023
In
vertebrate
vision,
early
retinal
circuits
divide
incoming
visual
information
into
functionally
opposite
elementary
signals:
On
and
Off,
transient
sustained,
chromatic
achromatic.
Together
these
signals
can
yield
an
efficient
representation
of
the
scene
for
transmission
to
brain
via
optic
nerve.
However,
this
long-standing
interpretation
function
is
based
on
mammals,
it
unclear
whether
functional
arrangement
common
all
vertebrates.
Here
we
show
that
male
poultry
chicks
use
a
fundamentally
different
strategy
communicate
from
eye
brain.
Rather
than
using
pairs
output
channels,
encode
polarity,
timing,
spectral
composition
stimuli
in
highly
correlated
manner:
fast
achromatic
encoded
by
Off-circuits,
slow
overwhelmingly
On-circuits.
Moreover,
most
channels
combine
On-
Off-circuits
simultaneously
encode,
or
multiplex,
both
information.
Our
results
birds
conform
evidence
fish,
amphibians,
reptiles
which
retain
full
ancestral
complement
four
types
cone
photoreceptors.
Proceedings of the National Academy of Sciences,
Journal Year:
2023,
Volume and Issue:
120(18)
Published: April 25, 2023
The
Old
World
macaque
monkey
and
New
common
marmoset
provide
fundamental
models
for
human
visual
processing,
yet
the
ancestral
lineage
diverged
from
these
lineages
over
25
Mya.
We
therefore
asked
whether
fine-scale
synaptic
wiring
in
nervous
system
is
preserved
across
three
primate
families,
despite
long
periods
of
independent
evolution.
applied
connectomic
electron
microscopy
to
specialized
foveal
retina
where
circuits
highest
acuity
color
vision
reside.
Synaptic
motifs
arising
cone
photoreceptor
type
sensitive
short
(S)
wavelengths
associated
with
"blue-yellow"
(S-ON
S-OFF)
color-coding
circuitry
were
reconstructed.
found
that
distinctive
arises
S
cones
each
species.
contacted
neighboring
L
M
(long-
middle-wavelength
sensitive)
humans,
but
such
contacts
rare
or
absent
macaques
marmosets.
discovered
a
major
S-OFF
pathway
established
its
absence
Further,
S-ON
chromatic
pathways
make
excitatory-type
types
not
Our
results
predict
early-stage
signals
are
distinct
imply
solving
connectome
at
nanoscale
level
will
be
critical
fully
understanding
neural
basis
vision.