bioRxiv (Cold Spring Harbor Laboratory),
Journal Year:
2024,
Volume and Issue:
unknown
Published: Feb. 23, 2024
ABSTRACT
The
firing
rate
is
a
prevalent
concept
used
to
describe
neural
computations,
but
estimating
dynamically
changing
rates
from
irregular
spikes
challenging.
An
inhomogeneous
Poisson
process,
the
standard
model
for
partitioning
and
spiking
irregularity,
cannot
account
diverse
spike
statistics
observed
across
neurons.
We
introduce
doubly
stochastic
renewal
point
flexible
mathematical
framework
variability,
which
captures
broad
spectrum
of
irregularity
periodic
super-Poisson.
validate
our
using
intracellular
voltage
recordings
develop
method
data.
find
that
cortical
neurons
decreases
sensory
association
areas
nearly
constant
each
neuron
under
many
conditions
can
also
change
task
epochs.
A
network
shows
depends
on
connectivity
with
external
input.
These
results
help
improve
precision
single
trials
constrain
mechanistic
models
circuits.
Physical Review Research,
Journal Year:
2023,
Volume and Issue:
5(4)
Published: Oct. 16, 2023
The
Lyapunov
spectrum
of
recurrent
neural
networks
is
calculated
and
analytical
approximations
through
random
matrix
theory
are
provided.
dependency
attractor
dimensions
entropy
rates
on
coupling
strength
input
fluctuations
identified
a
point
symmetry
the
revealed.
A
link
shown
between
exponents
to
error
propagation
stability
in
trained
for
machine-learning
applications.
The Journal of Physiology,
Journal Year:
2025,
Volume and Issue:
unknown
Published: Feb. 18, 2025
Abstract
Understanding
flexibility
in
the
neural
control
of
movement
requires
identifying
distribution
common
inputs
to
motor
units.
In
this
study,
we
identified
large
samples
units
from
two
lower
limb
muscles:
vastus
lateralis
(VL;
up
60
per
participant)
and
gastrocnemius
medialis
(GM;
67
participant).
First,
applied
a
linear
dimensionality
reduction
method
assess
manifolds
underlying
unit
activity.
We
subsequently
investigated
under
conditions:
sinusoidal
contractions
with
torque
feedback,
online
visual
feedback
on
firing
rates.
Overall,
found
that
activity
GM
was
effectively
captured
by
single
latent
factor
defining
unidimensional
manifold,
whereas
VL
were
better
represented
three
factors
multidimensional
manifold.
Despite
difference
dimensionality,
recruitment
muscles
exhibited
similarly
low
levels
flexibility.
Using
spiking
network
model,
tested
hypothesis
derived
factorization
does
not
solely
represent
descending
cortical
commands
but
is
also
influenced
spinal
circuitry.
demonstrated
heterogeneous
units,
or
specific
configurations
recurrent
inhibitory
circuits,
could
produce
This
study
clarifies
an
important
debated
issue,
demonstrating
while
firings
non‐compartmentalized
muscle
can
lie
CNS
may
still
have
limited
capacity
for
flexible
these
image
Key
points
To
generate
movement,
distributes
both
excitatory
The
level
remains
topic
debate
significant
implications
smallest
control.
By
combining
experimental
data
silico
models,
sample
be
manifold;
however,
show
very
their
recruitment.
manifold
directly
reflect
instead
relate
organization
local
circuits.
Neural Computation,
Journal Year:
2024,
Volume and Issue:
36(5), P. 803 - 857
Published: April 23, 2024
Abstract
Deep
feedforward
and
recurrent
neural
networks
have
become
successful
functional
models
of
the
brain,
but
they
neglect
obvious
biological
details
such
as
spikes
Dale’s
law.
Here
we
argue
that
these
are
crucial
in
order
to
understand
how
real
circuits
operate.
Towards
this
aim,
put
forth
a
new
framework
for
spike-based
computation
low-rank
excitatory-inhibitory
spiking
networks.
By
considering
populations
with
rank-1
connectivity,
cast
each
neuron’s
threshold
boundary
low-dimensional
input-output
space.
We
then
show
combined
thresholds
population
inhibitory
neurons
form
stable
space,
those
excitatory
an
unstable
boundary.
Combining
two
boundaries
results
rank-2
(EI)
network
inhibition-stabilized
dynamics
at
intersection
boundaries.
The
resulting
can
be
understood
difference
convex
functions
is
thereby
capable
approximating
arbitrary
non-linear
mappings.
demonstrate
several
properties
networks,
including
noise
suppression
amplification,
irregular
activity
synaptic
balance,
well
relate
rate
limit
becomes
soft.
Finally,
while
our
work
focuses
on
small
(5-50
neurons),
discuss
potential
avenues
scaling
up
much
larger
Overall,
proposes
perspective
may
serve
starting
point
mechanistic
understanding
computation.
Current Opinion in Neurobiology,
Journal Year:
2023,
Volume and Issue:
83, P. 102798 - 102798
Published: Oct. 30, 2023
The
degeneration
of
mesencephalic
dopaminergic
neurons
that
innervate
the
basal
ganglia
is
responsible
for
cardinal
motor
symptoms
Parkinson's
disease
(PD).
It
has
been
thought
loss
signaling
in
one
region
-
striatum
was
solely
network
pathophysiology
causing
PD
symptoms.
While
our
understanding
dopamine
(DA)'s
role
modulating
striatal
circuitry
deepened
recent
years,
it
also
become
clear
acts
other
regions
to
influence
movement.
Underscoring
this
point,
examination
a
new
progressive
mouse
model
shows
DA
depletion
alone
not
sufficient
induce
parkinsonism
and
restoration
extra-striatal
attenuates
parkinsonian
deficits
once
they
appear.
This
review
summarizes
advances
effort
understand
circuitry,
its
modulation
by
DA,
how
dysfunction
drives
Frontiers in Computational Neuroscience,
Journal Year:
2024,
Volume and Issue:
18
Published: Feb. 23, 2024
In
this
study,
we
focus
on
training
recurrent
spiking
neural
networks
to
generate
spatiotemporal
patterns
in
the
form
of
closed
two-dimensional
trajectories.
Spike
trains
trained
are
examined
terms
their
dissimilarity
using
Victor–Purpura
distance.
We
apply
algebraic
topology
methods
matrices
obtained
by
rank-ordering
entries
distance
matrices,
specifically
calculating
persistence
barcodes
and
Betti
curves.
By
comparing
features
different
types
output
patterns,
uncover
complex
relations
between
low-dimensional
target
signals
underlying
multidimensional
spike
trains.
Hippocampome.org
is
a
mature
open-access
knowledge
base
of
the
rodent
hippocampal
formation
focusing
on
neuron
types
and
their
properties.
Previously,
v1.0
established
foundational
classification
system
identifying
122
based
axonal
dendritic
morphologies,
main
neurotransmitter,
membrane
biophysics,
molecular
expression
(Wheeler
et
al.,
2015).
Releases
v1.1
through
v1.12
furthered
aggregation
literature-mined
data,
including
among
others
counts,
spiking
patterns,
synaptic
physiology,
in
vivo
firing
phases,
connection
probabilities.
Those
additional
properties
increased
online
information
content
this
public
resource
over
100-fold,
enabling
numerous
independent
discoveries
by
scientific
community.
v2.0,
introduced
here,
besides
incorporating
50
new
types,
now
recenters
its
focus
extending
functionality
to
build
real-scale,
biologically
detailed,
data-driven
computational
simulations.
In
all
cases,
freely
downloadable
model
parameters
are
directly
linked
specific
peer-reviewed
empirical
evidence
from
which
they
were
derived.
Possible
research
applications
include
quantitative,
multiscale
analyses
circuit
connectivity
neural
network
simulations
activity
dynamics.
These
advances
can
help
generate
precise,
experimentally
testable
hypotheses
shed
light
mechanisms
underlying
associative
memory
spatial
navigation.
Physical Review Letters,
Journal Year:
2025,
Volume and Issue:
134(1)
Published: Jan. 6, 2025
Can
spiking
neural
networks
(SNNs)
approximate
the
dynamics
of
recurrent
networks?
Arguments
in
classical
mean-field
theory
based
on
laws
large
numbers
provide
a
positive
answer
when
each
neuron
network
has
many
"duplicates",
i.e.,
other
neurons
with
almost
perfectly
correlated
inputs.
Using
disordered
model
that
guarantees
absence
duplicates,
we
show
duplicate-free
SNNs
can
converge
to
networks,
thanks
concentration
measure
phenomenon.
This
result
reveals
general
mechanism
underlying
emergence
rate-based
SNNs.
Frontiers in Synaptic Neuroscience,
Journal Year:
2023,
Volume and Issue:
15
Published: June 28, 2023
For
roughly
the
last
30
years,
notion
that
striatal
dopamine
(DA)
depletion
was
critical
determinant
of
network
pathophysiology
underlying
motor
symptoms
Parkinson's
disease
(PD)
has
dominated
field.
While
basal
ganglia
circuit
model
underpinning
this
hypothesis
been
great
heuristic
value,
itself
never
directly
tested.
Moreover,
studies
in
couple
decades
have
made
it
clear
fails
to
incorporate
key
features
ganglia,
including
fact
DA
acts
throughout
not
just
striatum.
Underscoring
point,
recent
work
using
a
progressive
mouse
PD
shown
alone
is
sufficient
induce
parkinsonism
and
restoration
extra-striatal
signaling
attenuates
parkinsonian
deficits
once
they
appear.
Given
broad
array
discoveries
field,
time
for
new
determinants
disability
PD.