Communications Biology,
Год журнала:
2025,
Номер
8(1)
Опубликована: Янв. 16, 2025
The
prefrontal
cortex
(PFC)
is
vital
for
higher
cognitive
functions
and
displays
neuronal
heterogeneity,
with
activity
varying
significantly
across
individual
neurons.
Using
calcium
imaging
in
the
medial
PFC
(mPFC)
of
mice,
we
investigate
whether
differences
degree
centrality-a
measure
connectivity
strength
within
local
circuits-could
explain
this
diversity
its
functional
implications.
In
young
adults,
neurons
high
centrality,
inferred
from
resting-state
activity,
exhibit
reliable
stable
action-plan
selectivity
during
memory-guided
tasks,
suggesting
that
closely
linked
to
heterogeneity.
This
relationship,
however,
deteriorates
middle-aged
older
mice.
A
computational
model
simulating
age-related
declines
synaptic
plasticity
reproduces
these
results.
centrality
also
predicts
cross-modal
selectivity,
but
predictive
power
diminishes
age.
Furthermore,
are
spatially
clustered,
a
pattern
fades
aging.
These
findings
reveal
significant
aging
impact
on
network
properties
parallel
spatial
organization
mPFC.
Trends in Cognitive Sciences,
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 1, 2025
Episodic
memory
must
accomplish
two
adversarial
goals:
encoding
and
storing
a
multitude
of
experiences
without
exceeding
the
finite
neuronal
structure
brain,
recalling
memories
in
vivid
detail.
Dimensionality
reduction
expansion
('dimensionality
transformation')
enable
brain
to
meet
these
demands.
Reduction
compresses
sensory
input
into
simplified,
storable
codes,
while
reconstructs
details.
Although
processes
are
essential
memory,
their
neural
mechanisms
for
episodic
remain
unclear.
Drawing
on
recent
insights
from
cognitive
psychology,
systems
neuroscience,
neuroanatomy,
we
propose
accounts
how
dimensionality
transformation
occurs
brain:
structurally
(via
corticohippocampal
pathways)
functionally
(through
oscillations).
By
examining
cross-species
evidence,
highlight
that
may
support
identify
crucial
questions
future
research.
iScience,
Год журнала:
2025,
Номер
28(3), С. 111936 - 111936
Опубликована: Янв. 31, 2025
Neural
dynamics
are
thought
to
reflect
computations
that
relay
and
transform
information
in
the
brain.
Previous
studies
have
identified
neural
population
many
individual
brain
regions
as
a
trajectory
geometry,
preserving
common
computational
motif.
However,
whether
these
populations
share
particular
geometric
patterns
across
brain-wide
remains
unclear.
Here,
by
mapping
widely
temporal/frontal/limbic
cortical
subcortical
structures
of
monkeys,
we
show
10
populations,
including
2,500
neurons,
propagate
visual
item
stochastic
manner.
We
found
inputs
predominantly
evoked
rotational
higher-order
area,
TE,
its
downstream
striatum
tail,
while
curvy/straight
appeared
frequently
orbitofrontal/hippocampal
network.
These
changes
were
not
deterministic
but
rather
according
their
respective
emergence
rates.
Our
meta-analysis
results
indicate
propagates
heterogeneous
mixture
signals
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 2, 2025
Abstract
Recent
advancements
in
genetically
encoded
calcium
indicators,
particularly
those
based
on
green
fluorescent
proteins,
have
optimized
their
performance
for
monitoring
neuronal
activities
a
variety
of
model
organisms.
However,
progress
developing
red-shifted
GECIs,
despite
advantages
over
has
been
slower,
resulting
fewer
options
end-users.
In
this
study,
we
explored
topological
inversion
and
soma-targeting
strategies,
which
are
complementary
to
conventional
mutagenesis,
re-engineer
red
indicator,
FRCaMP,
enhanced
vivo
performance.
The
sensors,
FRCaMPi
soma-targeted
(SomaFRCaMPi),
exhibit
up
2-fold
higher
dynamic
range
peak
ΔF/F
0
per
single
AP
compared
widely
used
jRGECO1a
neurons
culture
.
Compared
FRCaMPi,
SomaFRCaMPi
reduces
erroneous
correlation
activity
the
brains
mice
zebrafish
by
two-
four-fold
due
diminished
neuropil
contamination
without
compromising
signal-to-noise
ratio.
Under
wide-field
imaging
primary
somatosensory
visual
cortex
with
high
labeling
density
(80-90%),
exhibits
40%
SNR
decreased
artifactual
across
neurons.
Altogether,
improves
accuracy
scale
at
single-neuron
resolution
densely
labeled
brain
tissues
2-3-fold
automated
segmentation,
50%
fraction
responsive
cells,
jRGECO1a.
Our
findings
highlight
potential
SomaFRCaMPi,
comparable
most
sensitive
GCaMP,
precise
spatial
recording
populations
using
popular
modalities
organisms
such
as
mice.
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 23, 2025
ABSTRACT
As
we
listen
to
speech,
our
brains
actively
compute
the
meaning
of
individual
words.
Inspired
by
success
large
language
models
(LLMs),
hypothesized
that
brain
employs
vectorial
coding
principles,
such
is
reflected
in
distributed
activity
single
neurons.
We
recorded
responses
hundreds
neurons
human
hippocampus,
which
has
a
well-established
role
semantic
coding,
while
participants
listened
narrative
speech.
find
encoding
contextual
word
simultaneous
whose
selectivities
span
multiple
unrelated
categories.
Like
embedding
vectors
models,
distance
between
neural
population
correlates
with
distance;
however,
this
effect
was
only
observed
(like
BERT)
and
reversed
non-contextual
Word2Vec),
suggesting
depends
critically
on
contextualization.
Moreover,
for
subset
highly
semantically
similar
words,
even
embedders
showed
an
inverse
correlation
distances;
attribute
pattern
noise-mitigating
benefits
contrastive
coding.
Finally,
further
support
critical
context,
range
covaries
lexical
polysemy.
Ultimately,
these
results
hypothesis
hippocampus
follows
principles.
Understanding
neural
activity
organization
is
vital
for
deciphering
brain
function.
By
recording
whole-brain
calcium
in
larval
zebrafish
during
hunting
and
spontaneous
behaviors,
we
find
that
the
shape
of
space,
described
by
covariance
spectrum,
scale-invariant:
a
smaller,
randomly
sampled
cell
assembly
resembles
entire
brain.
This
phenomenon
can
be
explained
Euclidean
Random
Matrix
theory,
where
neurons
are
reorganized
from
anatomical
to
functional
positions
based
on
their
correlations.
Three
factors
contribute
observed
scale
invariance:
slow
correlation
decay,
higher
space
dimension,
heterogeneity.
In
addition
matching
data
mice,
our
theory
analysis
demonstrate
how
geometry
evolves
with
population
sizes
sampling
methods,
thus
revealing
an
organizing
principle
brain-wide
activity.
Coordinated
forelimb
actions,
such
as
reaching
and
grasping,
rely
on
motor
commands
that
span
a
spectrum
from
abstract
target
specification
to
detailed
instantaneous
muscle
control.
The
sensorimotor
cortex
is
central
controlling
these
complex
movements,
yet
how
the
command
signals
are
distributed
across
its
numerous
subregions
remains
unclear.
In
particular,
in
mice
it
unknown
if
primary
(M1)
somatosensory
(S1)
cortices
represent
low-level
joint
angle
details
addition
high-level
like
movement
direction.
Here,
we
combine
high
quality
markerless
tracking
two-photon
imaging
during
reach-to-grasp
task
quantify
movement-related
activity
mouse
caudal
area
(CFA)
S1
(fS1).
Linear
decoding
models
reveal
strong
representation
of
proximal
distal
angles
both
areas,
areas
support
with
comparable
fidelity.
Despite
shared
encoding,
time
course
target-specific
information
varied
areas.
CFA
exhibited
early
onset
sustained
encoding
while
fS1
was
more
transiently
modulated
around
lift
onset.
These
results
unique
contributions
implicating
cortical
circuit
for
control
than
has
been
previously
considered.
