Visual evoked potentials waveform analysis to measure intracortical damage in a preclinical model of multiple sclerosis
Frontiers in Cellular Neuroscience,
Journal Year:
2023,
Volume and Issue:
17
Published: May 31, 2023
Visual
evoked
potentials
(VEPs)
are
a
non-invasive
technique
routinely
used
in
clinical
and
preclinical
practice.
Discussion
about
inclusion
of
VEPs
McDonald
criteria,
for
Multiple
Sclerosis
(MS)
diagnosis,
increased
the
importance
VEP
MS
models.
While
interpretation
N1
peak
is
recognized,
less
known
first
second
positive
peaks,
P1
P2,
implicit
time
different
segments.
Our
hypothesis
that
P2
latency
delay
describes
intracortical
neurophysiological
dysfunction
from
visual
cortex
to
other
cortical
areas.
Language: Английский
Neural mechanisms of the temporal response of cortical neurons to intracortical microstimulation
bioRxiv (Cold Spring Harbor Laboratory),
Journal Year:
2023,
Volume and Issue:
unknown
Published: Oct. 17, 2023
ABSTRACT
Background
Intracortical
microstimulation
(ICMS)
is
used
to
map
neuronal
circuitry
in
the
brain
and
restore
lost
sensory
function,
including
vision,
hearing,
somatosensation.
The
temporal
response
of
cortical
neurons
single
pulse
ICMS
remarkably
stereotyped
comprises
short
latency
excitation
followed
by
prolonged
inhibition
and,
some
cases,
rebound
excitation.
However,
neural
origin
different
components
are
poorly
understood,
interactions
between
three
during
trains
pulses
remains
unclear.
Objective
We
computational
modeling
determine
mechanisms
contributing
model
pyramidal
neurons.
Methods
built
a
biophysically
based
column
comprising
with
realistic
morphology
synapses
quantified
protocols.
characterized
responses
across
stimulation
intensities
inhibitory
(GABA-B/GABA-A)
synaptic
strengths.
To
probe
components,
we
paired
at
inter-pulse
intervals
frequencies.
Finally,
evaluated
performance
biomimetic
evoking
sustained
response.
Results
Single
evoked
period
inhibition,
but
did
not
exhibit
post-inhibitory
strength
increased
duration
amplitude.
Prolonged
resulted
from
both
after-hyperpolarization
currents
GABA-B
transmission.
During
protocol,
test
decreased
marginally
compared
those
for
interpulse
(IPI)
<100
ms.
Further,
was
IPIs
<
40ms
predicted
linear
superposition
individual
responses.
For
IPIs>40
ms,
comparable
pulse.
Short
repetitive
excitatory
against
background
inhibition.
declined
higher
cessation
frequencies
following
Biomimetic
onset
offset
phases
despite
presence
induced
Conclusions
replicated
long-lasting
documented
experimental
studies.
Both
cellular
influenced
generated
ICMS.
non-linear
dynamic
ICMS-evoked
activity
may
play
an
important
role
mediating
ICMS-induced
precepts.
HIGHLIGHTS
Implemented
study
intracortical
Temporal
comprised
include
Excitation
mediated
direct
(antidromic)
indirect
(after-hyperpolarizing
currents)
(GABAergic)
mechanisms.
dynamics
should
be
considered
when
designing
paradigms
prosthetic
applications.
Language: Английский
Effect of anesthesia in rats on measures of complexity, differentiation, and integrated information
Published: June 14, 2023
To
investigate
proposed
mechanisms
behind
loss
of
consciousness,
it
is
important
to
extend
the
current
state
field
in
human
research
rodents.
Perturbational
complexity
index
(PCI)
a
promising
metric
“capacity
for
consciousness”
humans.
PCI
based
on
perturbational
approach
that
allows
inferring
system’s
capacity
causal
integration
and
differentiation
information.
However,
technically
demanding
time-consuming.
Thus,
measures
spontaneous
EEG
recordings
may
be
more
practical
certain
clinical
purposes.
Furthermore,
while
might
better
assess
information
processing,
analysis
indicative
ongoing
dynamics.
Here,
we
compare
range
EEG-based
signal
diversity
integrated
rats
undergoing
propofol,
sevoflurane,
ketamine
anesthesia.We
find
Lempel-Ziv
complexity,
amplitude
coalition
entropy,
geometric
are
able
distinguish
between
awake
anesthesia,
all
implemented
(except
synchrony
entropy)
were
rank-order
correlated
with
PCI.
In
addition,
decreased
anesthesia
ketamine),
several
increased,
contrary
expectations.
Based
divergence
network
properties
estimated
from
directed
functional
connectivity
(current
results)
effective
(earlier
results),
speculate
disrupt
global
cortico-cortical
transfer,
as
suggested
by
perturbation-based
approaches,
activity
appear
suggest
opposite
because
driving
subcortical
projections
e.g.
thalamus,
or
suppressed
encoding
specificity
Language: Английский