The
processing
of
visual
information
by
retinal
starburst
amacrine
cells
(SACs)
involves
transforming
excitatory
input
from
bipolar
(BCs)
into
directional
calcium
output.
While
previous
studies
have
suggested
that
an
asymmetry
in
the
kinetic
properties
along
soma-dendritic
axes
postsynaptic
cell
could
enhance
tuning
at
level
individual
branches,
it
remains
unclear
whether
biologically
relevant
presynaptic
kinetics
contribute
to
direction
selectivity
when
stimulation
engages
entire
dendritic
tree.
To
address
this
question,
we
built
multicompartmental
models
bipolar–SAC
circuit
and
trained
them
boost
tuning.
We
report
despite
significant
crosstalk
dissimilar
preferences
dendrites
occur
during
whole-cell
stimulation,
rules
guide
BC
leading
optimal
are
similar
single-dendrite
condition.
correlate
model
predictions
empirical
findings,
utilized
two-photon
glutamate
imaging
study
dynamics
release
onto
ON-
OFF-starburst
murine
retina.
reveal
diverse
response
motion
both
populations;
algorithms
on
experimental
data
differences
temporal
likely
correspond
heterogeneous
receptive
field
(RF)
among
different
types,
including
spatial
extent
center
surround
components.
In
addition,
demonstrate
architecture
composed
units
with
experimentally
recorded
drive
but
not
levels
replicate
suggesting
other
DS
mechanisms
required
explain
SAC
function.
Our
provides
new
insights
complex
underlying
highlights
potential
contribution
computation
cells.
The Journal of General Physiology,
Год журнала:
2024,
Номер
156(8)
Опубликована: Июнь 5, 2024
Cholinergic
signaling
in
the
retina
is
mediated
by
acetylcholine
(ACh)
released
from
starburst
amacrine
cells
(SACs),
which
are
key
neurons
for
motion
detection.
SACs
comprise
ON
and
OFF
subtypes,
morphologically
show
mirror
symmetry
to
each
other.
Although
many
physiological
studies
on
have
targeted
only,
synaptic
computation
of
assumed
be
similar.
Recent
demonstrated
that
gene
expression
patterns
receptor
types
differed
between
SACs,
suggesting
differences
their
functions.
Here,
we
compared
cholinergic
pathways
mouse
using
patch
clamp
technique.
The
application
ACh
increased
GABAergic
feedback,
observed
as
postsynaptic
currents
both
SACs;
however,
mode
feedback
differed.
Nicotinic
receptors
while
muscarinic
only
adults.
Neither
tetrodotoxin,
blocked
action
potentials,
nor
LY354740,
neurotransmitter
release
eliminated
ACh-induced
SACs.
These
results
suggest
regulated
different
mechanisms
adults
non-spiking
other
than
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2023,
Номер
unknown
Опубликована: Авг. 5, 2023
The
processing
of
visual
information
by
retinal
starburst
amacrine
cells
(SACs)
involves
transforming
excitatory
input
from
bipolar
(BCs)
into
directional
calcium
output.
While
previous
studies
have
suggested
that
an
asymmetry
in
the
kinetic
properties
along
soma-dendritic
axes
postsynaptic
cell
could
enhance
tuning
at
level
individual
branches,
it
remains
unclear
whether
biologically
relevant
presynaptic
kinetics
contribute
to
direction
selectivity
when
stimulation
engages
entire
dendritic
tree.
To
address
this
question,
we
built
multicompartmental
models
bipolar-SAC
circuit
and
trained
them
boost
tuning.
We
report
despite
significant
crosstalk
dissimilar
preferences
dendrites
occur
during
whole-cell
stimulation,
rules
guide
BC
leading
optimal
are
similar
single-dendrite
condition.
correlate
model
predictions
empirical
findings,
utilized
two-photon
glutamate
imaging
study
dynamics
release
onto
ON-
OFF-starburst
murine
retina.
reveal
diverse
response
motion
both
populations;
algorithms
on
experimental
data
differences
temporal
likely
correspond
heterogeneous
receptive
field
(RF)
among
different
types,
including
spatial
extent
center
surround
components.
In
addition,
demonstrate
architecture
composed
units
with
experimentally
recorded
drive
but
not
levels
replicate
suggesting
other
DS
mechanisms
required
explain
SAC
function.
Our
provides
new
insights
complex
underlying
highlights
potential
contribution
computation
cells.
Frontiers in Ophthalmology,
Год журнала:
2023,
Номер
3
Опубликована: Авг. 29, 2023
The
retina
is
comprised
of
diverse
neural
networks,
signaling
from
photoreceptors
to
ganglion
cells
encode
images.
synaptic
connections
between
these
retinal
neurons
are
crucial
points
for
information
transfer;
however,
the
input-output
relations
many
synapses
understudied.
Starburst
amacrine
in
known
contribute
motion
detection
circuits,
providing
a
unique
window
understanding
computations.
We
examined
dual
transmitter
release
GABA
and
acetylcholine
starburst
by
optogenetic
activation
cells,
conducted
patch
clamp
recordings
postsynaptic
record
excitatory
inhibitory
currents
(EPSCs
IPSCs).
As
exhibit
distinct
kinetics
response
objects
moving
preferred
or
null
direction,
we
mimicked
their
depolarization
using
stimuli
varying
slopes
rising
phase.
amplitudes
EPSCs
IPSCs
were
reduced
as
stimulus
speed
was
prolonged.
However,
sensitivity
slope
differed.
EPSC
consistently
steepness
phase
fell.
By
contrast,
less
sensitive
rise
maintained
until
became
shallow.
These
results
indicate
that
mechanisms
which
could
cells’
direction
selectivity.
The
processing
of
visual
information
by
retinal
starburst
amacrine
cells
(SACs)
involves
transforming
excitatory
input
from
bipolar
(BCs)
into
directional
calcium
output.
While
previous
studies
have
suggested
that
an
asymmetry
in
the
kinetic
properties
along
soma-dendritic
axes
postsynaptic
cell
could
enhance
tuning
at
level
individual
branches,
it
remains
unclear
whether
biologically
relevant
presynaptic
kinetics
contribute
to
direction
selectivity
when
stimulation
engages
entire
dendritic
tree.
To
address
this
question,
we
built
multicompartmental
models
bipolar–SAC
circuit
and
trained
them
boost
tuning.
We
report
despite
significant
crosstalk
dissimilar
preferences
dendrites
occur
during
whole-cell
stimulation,
rules
guide
BC
leading
optimal
are
similar
single-dendrite
condition.
correlate
model
predictions
empirical
findings,
utilized
two-photon
glutamate
imaging
study
dynamics
release
onto
ON-
OFF-starburst
murine
retina.
reveal
diverse
response
motion
both
populations;
algorithms
on
experimental
data
differences
temporal
likely
correspond
heterogeneous
receptive
field
(RF)
among
different
types,
including
spatial
extent
center
surround
components.
In
addition,
demonstrate
architecture
composed
units
with
experimentally
recorded
drive
but
not
levels
replicate
suggesting
other
DS
mechanisms
required
explain
SAC
function.
Our
provides
new
insights
complex
underlying
highlights
potential
contribution
computation
cells.
The
processing
of
visual
information
by
retinal
starburst
amacrine
cells
(SACs)
involves
transforming
excitatory
input
from
bipolar
(BCs)
into
directional
calcium
output.
While
previous
studies
have
suggested
that
an
asymmetry
in
the
kinetic
properties
along
soma-dendritic
axes
postsynaptic
cell
could
enhance
tuning
at
level
individual
branches,
it
remains
unclear
whether
biologically
relevant
presynaptic
kinetics
contribute
to
direction
selectivity
when
stimulation
engages
entire
dendritic
tree.
To
address
this
question,
we
built
multicompartmental
models
bipolar–SAC
circuit
and
trained
them
boost
tuning.
We
report
despite
significant
crosstalk
dissimilar
preferences
dendrites
occur
during
whole-cell
stimulation,
rules
guide
BC
leading
optimal
are
similar
single-dendrite
condition.
correlate
model
predictions
empirical
findings,
utilized
two-photon
glutamate
imaging
study
dynamics
release
onto
ON-
OFF-starburst
murine
retina.
reveal
diverse
response
motion
both
populations;
algorithms
on
experimental
data
differences
temporal
likely
correspond
heterogeneous
receptive
field
(RF)
among
different
types,
including
spatial
extent
center
surround
components.
In
addition,
demonstrate
architecture
composed
units
with
experimentally
recorded
drive
but
not
levels
replicate
suggesting
other
DS
mechanisms
required
explain
SAC
function.
Our
provides
new
insights
complex
underlying
highlights
potential
contribution
computation
cells.