Optogenetics
allows
manipulations
of
genetically
and
spatially
defined
neuronal
populations
with
excellent
temporal
control.
However,
neurons
are
coupled
other
over
multiple
length
scales,
the
effects
localized
thus
spread
beyond
targeted
neurons.
We
benchmarked
several
optogenetic
methods
to
inactivate
small
regions
neocortex.
Optogenetic
excitation
GABAergic
produced
more
effective
inactivation
than
light-gated
ion
pumps.
Transgenic
mice
expressing
light-dependent
chloride
channel
GtACR1
most
potent
inactivation.
Generally,
substantially
photostimulation
light,
caused
by
strong
coupling
between
cortical
Over
some
range
light
intensity,
inhibitory
reduced
activity
in
these
neurons,
together
pyramidal
a
signature
inhibition-stabilized
neural
networks
('paradoxical
effect').
The
offset
was
followed
rebound
dose-dependent
manner,
limiting
resolution.
Our
data
offer
guidance
for
design
vivo
optogenetics
experiments.
Scientific Reports,
Journal Year:
2016,
Volume and Issue:
6(1)
Published: March 16, 2016
Balance
of
excitation
and
inhibition
is
a
fundamental
feature
in
vivo
network
activity
important
for
its
computations.
However,
presence
the
neocortex
higher
mammals
not
well
established.
We
investigated
dynamics
using
dense
multielectrode
recordings
humans
monkeys.
found
that
all
states
wake-sleep
cycle,
excitatory
inhibitory
ensembles
are
balanced,
co-fluctuate
with
slight
instantaneous
deviations
from
perfect
balance,
mostly
slow-wave
sleep.
Remarkably,
these
correlated
fluctuations
seen
many
different
temporal
scales.
The
similarity
computational
features
model
self-generated
balanced
suggests
such
essentially
generated
by
recurrent
local
due
to
external
inputs.
Finally,
we
find
this
balance
breaks
down
during
seizures,
where
correlation
populations
disrupted.
These
results
show
normal
brain
activity,
break
could
be
an
factor
define
pathological
states.
Science,
Journal Year:
2015,
Volume and Issue:
349(6243), P. 70 - 74
Published: July 3, 2015
Individual
cortical
neurons
can
selectively
respond
to
specific
environmental
features,
such
as
visual
motion
or
faces.
How
this
relates
the
selectivity
of
presynaptic
network
across
layers
remains
unclear.
We
used
single-cell-initiated,
monosynaptically
restricted
retrograde
transsynaptic
tracing
with
rabies
viruses
expressing
GCaMP6s
image,
in
vivo,
motion-evoked
activity
individual
layer
2/3
pyramidal
and
their
networks
mouse
primary
cortex.
Neurons
within
each
exhibited
similar
direction
preferences,
forming
layer-specific
functional
modules.
In
one-third
networks,
modules
were
locked
preference
postsynaptic
neuron,
whereas
for
other
varied
by
layer.
Thus,
there
exist
feature-locked
feature-variant
networks.
