Neuronal
ensembles,
coactive
groups
of
neurons
found
in
spontaneous
and
evoked
cortical
activity,
are
causally
related
to
memories
perception,
but
it
is
still
unknown
how
stable
or
flexible
they
over
time.
We
used
two-photon
multiplane
calcium
imaging
track
weeks
the
activity
same
pyramidal
layer
2/3
visual
cortex
from
awake
mice
recorded
their
visually
responses.
Less
than
half
remained
active
across
any
two
sessions.
These
formed
ensembles
that
lasted
weeks,
some
were
also
transient
appeared
only
one
single
session.
Stable
preserved
most
for
up
46
days,
our
longest
imaged
period,
these
'core'
cells
had
stronger
functional
connectivity.
Our
results
demonstrate
neuronal
can
last
could,
principle,
serve
as
a
substrate
long-lasting
representation
perceptual
states
memories.
Communications Biology,
Journal Year:
2024,
Volume and Issue:
7(1)
Published: March 26, 2024
Abstract
For
generations
researchers
have
been
observing
the
dynamic
processes
of
life
through
lens
a
microscope.
This
has
offered
tremendous
insights
into
biological
phenomena
that
span
multiple
orders
time-
and
length-scales
ranging
from
pure
magic
molecular
reorganization
at
membrane
immune
cells,
to
cell
migration
differentiation
during
development
or
wound
healing.
Standard
fluorescence
microscopy
techniques
offer
glimpses
such
in
vitro,
however,
when
applied
intact
systems,
they
are
challenged
by
reduced
signal
strengths
signal-to-noise
ratios
result
deeper
imaging.
As
remedy,
two-photon
excitation
(TPE)
takes
special
place,
because
it
allows
us
investigate
vivo,
their
natural
environment,
even
living
animal.
Here,
we
review
fundamental
principles
underlying
TPE
aimed
basic
advanced
users
interested
adopting
for
intravital
We
focus
on
applications
neurobiology,
present
current
trends
towards
faster,
wider
imaging,
discuss
combination
with
photon
counting
technologies
metabolic
imaging
spectroscopy,
as
well
highlight
outstanding
issues
drawbacks
application
these
methodologies.
Cell Reports,
Journal Year:
2018,
Volume and Issue:
22(11), P. 3087 - 3098
Published: March 1, 2018
Sensory
information
is
encoded
within
the
brain
in
distributed
spatiotemporal
patterns
of
neuronal
activity.
Understanding
how
these
influence
behavior
requires
a
method
to
measure
and
bidirectionally
perturb
with
high
spatial
resolution
activity
multiple
cell
types
engaged
sensory
processing.
Here,
we
combined
two-photon
holography
stimulate
neurons
expressing
blue
light-sensitive
opsins
(ChR2
GtACR2)
imaging
red-shifted
indicator
jRCaMP1a
mouse
neocortex
vivo.
We
demonstrate
efficient
control
neural
excitability
across
layers
holographic
stimulation
improved
by
opsin
somatic
targeting.
Moreover,
performed
simultaneous
bidirectional
manipulation
cellular
negligible
effect
beam
on
excitation.
This
all-optical
approach
represents
powerful
tool
causally
dissect
specified
ensembles
determine
function
animal
behavior.
Cell Reports,
Journal Year:
2018,
Volume and Issue:
24(5), P. 1243 - 1253.e5
Published: July 1, 2018
In
recent
decades,
optogenetics
has
been
transforming
neuroscience
research,
enabling
neuroscientists
to
drive
and
read
neural
circuits.
The
development
in
illumination
approaches
combined
with
two-photon
(2P)
excitation,
either
sequential
or
parallel,
opened
the
route
for
brain
circuit
manipulation
single-cell
resolution
millisecond
temporal
precision.
Yet,
high
excitation
power
required
multi-target
photostimulation,
especially
under
2P
illumination,
raises
questions
about
induced
local
heating
inside
samples.
Here,
we
present
experimentally
validate
a
theoretical
model
that
makes
it
possible
simulate
3D
light
propagation
heat
diffusion
optically
scattering
samples
at
spatial
configurations
most
commonly
used
perform
optogenetics:
single-
multi-spot
holographic
spiral
laser
scanning.
By
investigating
effects
of
photostimulation
repetition
rate,
spot
spacing,
dependence
diffusion,
found
conditions
make
design
experiment
minimal
sample
heating.
Journal of Neuroscience,
Journal Year:
2021,
Volume and Issue:
41(19), P. 4160 - 4168
Published: April 23, 2021
The
brain
functions
through
coordinated
activity
among
distributed
regions.
Wide-field
calcium
imaging,
combined
with
improved
genetically
encoded
indicators,
allows
sufficient
signal-to-noise
ratio
and
spatiotemporal
resolution
to
afford
a
unique
opportunity
capture
cortex-wide
dynamics
on
moment-by-moment
basis
in
behaving
animals.
Recent
applications
of
this
approach
have
been
uncovering
cortical
at
unprecedented
scales
during
various
cognitive
processes,
ranging
from
relatively
simple
sensorimotor
integration
more
complex
decision-making
tasks.
In
review,
we
will
highlight
recent
scientific
advances
enabled
by
wide-field
imaging
mice.
We
then
summarize
several
technical
considerations
future
opportunities
for
uncover
large-scale
circuit
dynamics.
