bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2022,
Номер
unknown
Опубликована: Окт. 5, 2022
Abstract
Metabolic
limitations
within
the
brain
frequently
arise
in
context
of
aging
and
disease.
As
largest
consumers
energy
brain,
ion
pumps
that
maintain
neuronal
membrane
potential
are
most
affected
when
supply
becomes
limited.
To
characterize
effects
such
limitations,
we
analyze
gradients
present
Larter-Breakspear
neural
mass
model.
We
show
existence
locations
Neimark-Sacker
period-doubling
bifurcations
sodium,
calcium,
potassium
reversal
potentials,
demonstrate
these
form
physiologically
relevant
bounds
gradient
variability.
Within
bounds,
how
depolarization
will
cause
decreased
activity.
also
decreases
inter-regional
coherence,
causing
a
shift
critical
point
at
which
coupling
occurs
thereby
inducing
loss
synchrony
between
regions.
In
this
way,
model
captures
variability
microscale
level
propagates
changes
to
macroscale
congruent
with
those
observed
human
neuroimaging
studies.
Journal of Neural Engineering,
Год журнала:
2024,
Номер
21(2), С. 021002 - 021002
Опубликована: Апрель 1, 2024
Abstract
Objective
:
Epilepsy
is
a
complex
disease
spanning
across
multiple
scales,
from
ion
channels
in
neurons
to
neuronal
circuits
the
entire
brain.
Over
past
decades,
computational
models
have
been
used
describe
pathophysiological
activity
of
epileptic
brain
different
aspects.
Traditionally,
each
model
can
aid
optimizing
therapeutic
interventions,
therefore,
providing
particular
view
design
strategies
for
treating
epilepsy.
As
result,
most
studies
are
concerned
with
generating
specific
that
help
us
understand
certain
machinery
pathological
state.
Those
vary
complexity
and
biological
accuracy,
system-level
often
lacking
details.
Approach
Here,
we
review
various
types
epilepsy
discuss
their
potential
approaches
scenarios,
including
drug
discovery,
surgical
strategies,
stimulation,
seizure
prediction.
We
propose
need
consider
an
integrated
approach
unified
modelling
framework
scales
Our
proposal
based
on
recent
increase
power,
which
has
opened
up
possibility
unifying
those
into
simulations
unprecedented
level
detail.
Main
results
A
multi-scale
bridge
gap
between
biologically
detailed
models,
address
molecular
cellular
questions,
brain-wide
abstract
account
neurological
behavioural
observations.
Significance
With
these
efforts,
move
toward
next
generation
capable
connecting
features,
such
as
channel
properties,
standard
clinical
measures
severity.
Nonlinear Analysis Real World Applications,
Год журнала:
2023,
Номер
75, С. 103986 - 103986
Опубликована: Авг. 17, 2023
In
contemporary
society,
social
networks
accelerate
decision
dynamics
causing
a
rapid
switch
of
opinions
in
number
fields,
including
the
prevention
infectious
diseases
by
means
vaccines.
This
that
opinion
can
nowadays
be
much
faster
than
spread
epidemics.
Hence,
we
propose
Susceptible–Infectious–Removed
epidemic
model
coupled
with
an
evolutionary
vaccination
game
embedding
public
health
system
efforts
to
increase
vaccine
uptake.
results
global
"epidemic
+
game".
The
epidemiological
novelty
this
work
is
assume
switching
strategy
"pro
vaccine"
depends
on
incidence
disease.
As
consequence
above-mentioned
accelerated
decisions,
acts
two
different
scales:
fast
scale
for
decisions
and
slower
Another,
more
methodological,
element
apply
Geometrical
Singular
Perturbation
Theory
(GSPT)
such
two-scale
then
compare
geometric
analysis
Quasi-Steady-State
Approximation
(QSSA)
approach,
showing
criticality
latter.
Later,
GSPT
approach
disease
prevalence-based
already
studied
(Della
Marca
d'Onofrio,
Comm
Nonl
Sci
Num
Sim,
2021)
via
QSSA
considering
medium–large
values
parameter.
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2022,
Номер
unknown
Опубликована: Июнь 16, 2022
Abstract
Neural
mass
models
(NMMs)
are
designed
to
reproduce
the
collective
dynamics
of
neuronal
populations.
A
common
framework
for
NMMs
assumes
heuristically
that
output
firing
rate
a
neural
population
can
be
described
by
static
nonlinear
transfer
function
(NMM1).
However,
recent
exact
mean-field
theory
quadratic
integrate-and-fire
(QIF)
neurons
challenges
this
view
showing
mean
is
not
state
but
follows
two
coupled
non-linear
differential
equations
(NMM2).
Here
we
analyze
and
compare
these
descriptions
in
presence
second-order
synaptic
dynamics.
First,
derive
mathematical
equivalence
between
infinitely
slow
synapse
limit,
i.e.,
show
NMM1
an
approximation
NMM2
regime.
Next,
evaluate
applicability
limit
context
realistic
physiological
parameter
values
analyzing
with
inhibitory
or
excitatory
synapses.
We
fails
important
dynamical
features
model,
such
as
self-sustained
oscillations
interneuron
QIF
network.
Furthermore,
model
one,
stimulation
pyramidal
cell
induces
resonant
oscillatory
activity
whose
peak
frequency
amplitude
increase
self-coupling
gain
external
input.
This
may
play
role
enhanced
response
densely
connected
networks
weak
uniform
inputs,
electric
fields
produced
non-invasive
brain
stimulation.
NeuroImage,
Год журнала:
2023,
Номер
274, С. 120137 - 120137
Опубликована: Апрель 26, 2023
This
paper
introduces
methods
and
a
novel
toolbox
that
efficiently
integrates
high-dimensional
Neural
Mass
Models
(NMMs)
specified
by
two
essential
components.
The
first
is
the
set
of
nonlinear
Random
Differential
Equations
(RDEs)
dynamics
each
neural
mass.
second
highly
sparse
three-dimensional
Connectome
Tensor
(CT)
encodes
strength
connections
delays
information
transfer
along
axons
connection.
To
date,
simplistic
assumptions
prevail
about
in
CT,
often
assumed
to
be
Dirac-delta
functions.
In
reality,
are
distributed
due
heterogeneous
conduction
velocities
connecting
masses.
These
distributed-delay
CTs
challenging
model.
Our
approach
implements
these
models
leveraging
several
innovations.
Semi-analytical
integration
RDEs
done
with
Local
Linearization
(LL)
scheme
for
mass,
ensuring
dynamical
fidelity
original
continuous-time
dynamic.
semi-analytic
LL
computationally-efficient.
addition,
tensor
representation
CT
facilitates
parallel
computation.
It
also
seamlessly
allows
modeling
any
level
complexity
or
realism.
ease
implementation
includes
CTs.
Consequently,
our
algorithm
scales
linearly
number
masses
equations
they
represented
with,
contrasting
more
traditional
scale
quadratically
at
best.
illustrate
toolbox's
usefulness,
we
simulate
single
Zetterberg-Jansen
Rit
(ZJR)
cortical
column,
thalmo-cortical
unit,
toy
example
comprising
1000
interconnected
ZJR
columns.
simulations
demonstrate
consequences
modifying
especially
introducing
delays.
examples
explaining
EEG
oscillations,
e.g.,
split
alpha
peaks,
since
only
appear
distinct
We
provide
an
open-source
Script
toolbox.
Journal of Circuits Systems and Computers,
Год журнала:
2023,
Номер
33(10)
Опубликована: Дек. 17, 2023
Motivated
by
the
study
of
multiple
time
scale
system
dynamics,
we
analyze
Murali–Lakshmanan–Chua
(MLC)
dissipative
circuit
exhibiting
periodic
bursting
with
different
types
oscillations
in
this
paper.
Such
patterns
can
be
analyzed
treating
slow
variable
as
a
parameter
nonsmooth
fast
subsystem.
The
discontinuous
bifurcation
structure
subsystem
described
generalized
differential
Clarke
and
Jacobian
matrix
system.
Bursting
well
oscillation
mechanisms
clarified
bifurcations,
series
phase
portraits.
For
chosen
values,
designed
admits
both
MLC
type
attractors
Duffing–van
der
Pol
attractors.
It
is
found
that
not
only
features
combined
parameters
system,
but
also
two
switching
boundaries
may
have
an
important
impact
on
origin
behaviors.
In
particular,
explicit
analytic
solutions
proposed
are
investigated
detail.
We
show
arise
from
either
saddle-node
or
passage
through
Hopf
bifurcation.
Finally,
validity
theoretical
analysis
has
been
verified
numerical
simulations.
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2023,
Номер
unknown
Опубликована: Май 11, 2023
Abstract
Aging
is
associated
with
impaired
signaling
between
brain
regions
when
measured
using
resting-state
fMRI.
This
age-related
destabilization
and
desynchronization
of
networks
reverses
itself
the
switches
from
metabolizing
glucose
to
ketones.
Here,
we
probe
mechanistic
basis
for
these
effects.
First,
established
their
neuronal
two
datasets
acquired
EEG
(
Lifespan:
standard
diet,
20-80
years,
N
=
201;
Metabolic:
individually
weight-dosed
calorically-matched
ketone
ester
challenge,
μ
age
26.9
±
11.2
36).
Then,
multi-scale
Larter-Breakspear
neural
mass
model,
identified
unique
set
parameters
consistent
our
clinical
data.
Together,
results
implicate
potassium
(K
+
)
gradient
dysregulation
as
a
mechanism
its
reversal
ketosis,
latter
finding
which
direct
measurement
ion
channels.