Nature Communications,
Год журнала:
2024,
Номер
15(1)
Опубликована: Окт. 23, 2024
Representational
drift-the
gradual
continuous
change
of
neuronal
representations-has
been
observed
across
many
brain
areas.
It
is
unclear
whether
drift
caused
by
synaptic
plasticity
elicited
sensory
experience,
or
the
intrinsic
volatility
synapses.
Here,
using
chronic
two-photon
calcium
imaging
in
primary
visual
cortex
female
mice,
we
find
that
preferred
stimulus
orientation
individual
neurons
slowly
drifts
over
course
weeks.
By
cylinder
lens
goggles
to
limit
experience
a
narrow
range
orientations,
show
direction
drift,
but
not
its
magnitude,
biased
statistics
input.
A
network
model
suggests
largely
results
from
volatility,
which
under
normal
conditions
counteracted
experience-driven
Hebbian
mechanisms,
stabilizing
orientation.
Under
deprivation
these
mechanisms
enable
adaptation.
Thus,
steers
match
environment.
The MIT Press eBooks,
Год журнала:
2024,
Номер
unknown
Опубликована: Фев. 27, 2024
An
exciting,
new
framework
for
interpreting
the
philosophical
significance
of
neuroscience.
All
science
needs
to
simplify,
but
when
object
research
is
something
as
complicated
brain,
this
challenge
can
stretch
limits
scientific
possibility.
In
fact,
in
The
Brain
Abstracted,
an
avowedly
“opinionated”
history
neuroscience,
M.
Chirimuuta
argues
that,
due
brain's
complexity,
neuroscientific
theories
have
only
captured
partial
truths—and
“neurophilosophy”
unlikely
be
achieved.
Looking
at
theory
and
practice
both
past
present,
shows
how
has
been
shaped
by
problem
brain
complexity
need,
science,
make
things
simple
possible.
From
history,
draws
lessons
debates
philosophy
over
definition
mind
explanations
consciousness
mind-body
problem.
Abstracted
product
a
historical
rupture
that
become
visible
twenty-first
century,
between
“classical”
approach,
which
seeks
simple,
intelligible
principles
underlying
manifest
nature,
data-driven
engineering
dispenses
with
search
elegant,
explanatory
laws
models.
space
created
rupture,
finds
grounds
theoretical
practical
humility.
Her
aim
not
reform
or
offer
advice
neuroscientists,
rather
interpret
their
work—and
suggest
Nature Communications,
Год журнала:
2024,
Номер
15(1)
Опубликована: Март 8, 2024
Abstract
Behavior
can
be
remarkably
consistent,
even
over
extended
time
periods,
yet
whether
this
is
reflected
in
stable
or
‘drifting’
neuronal
responses
to
task
features
remains
controversial.
Here,
we
find
a
persistently
active
ensemble
of
neurons
the
medial
prefrontal
cortex
(mPFC)
mice
that
reliably
maintains
trajectory-specific
tuning
several
weeks
while
performing
an
olfaction-guided
spatial
memory
task.
This
task-specific
reference
frame
stabilized
during
learning,
upon
which
repeatedly
show
little
representational
drift
and
maintain
their
across
long
pauses
exposure
repeated
changes
cue-target
location
pairings.
These
data
thus
suggest
‘core
ensemble’
forming
task-relevant
space
for
performance
consistent
behavior
periods
time.
Representational
drift
refers
to
the
dynamic
nature
of
neural
representations
in
brain
despite
behavior
being
seemingly
stable.
Although
has
been
observed
many
different
regions,
mechanisms
underlying
it
are
not
known.
Since
intrinsic
excitability
is
suggested
play
a
key
role
regulating
memory
allocation,
fluctuations
could
bias
reactivation
previously
stored
ensembles
and
therefore
act
as
motor
for
drift.
Here,
we
propose
rate-based
plastic
recurrent
network
with
slow
excitability.
We
first
show
that
subsequent
reactivations
ensemble
can
lead
this
ensemble.
The
model
predicts
induced
by
co-activation
active
neurons
along
high
which
leads
remodeling
weights.
Consistent
previous
experimental
works,
drifting
informative
about
its
temporal
history.
Crucially,
gradual
necessary
decoding
information
from
activity
Finally,
preserved
be
decoded
an
output
neuron
having
synapses
main
region.
Nature Communications,
Год журнала:
2023,
Номер
14(1)
Опубликована: Июль 21, 2023
Abstract
Primary
sensory
regions
are
believed
to
instantiate
stable
neural
representations,
yet
a
number
of
recent
rodent
studies
suggest
instead
that
representations
drift
over
time.
To
test
whether
in
human
visual
cortex,
we
analyzed
large
longitudinal
dataset
fMRI
responses
images
natural
scenes.
We
fit
the
using
an
image-computable
encoding
model
and
tested
how
well
generalized
across
sessions.
found
systematic
changes
fits
exhibited
cumulative
many
months.
Convergent
analyses
pinpoint
responsivity
as
source
drift,
while
population-level
representational
dissimilarities
between
stimuli
were
unchanged.
These
observations
downstream
cortical
areas
may
read-out
representation,
even
within
V1
exhibit
drift.
