Chaos An Interdisciplinary Journal of Nonlinear Science,
Год журнала:
2024,
Номер
34(12)
Опубликована: Дек. 1, 2024
We
present
numerical
results
on
the
effects
of
two
presynaptic
FitzHugh–Nagumo
neurons
a
postsynaptic
neuron
under
unidirectional
electrical
coupling.
The
affect
not
simultaneously
but
with
certain
time
shift.
consider
cases
where
amplitudes
spikes
can
be
both
higher
and
lower
than
excitation
threshold
level.
latter
case
receives
main
attention
in
our
work.
carefully
examine
conditions
which
is
excited
by
asynchronous
external
spikes.
With
arbitrarily
chosen
parameters,
almost
incapable
accumulating
energy
signals,
unlike,
for
example,
leaky
integrate-and-fire
neuron.
In
this
case,
only
excites
very
short
delay
between
impulses.
However,
we
have
discovered,
first
time,
parameter
region
possible
even
significant
delays
impulses
subthreshold
amplitudes.
explain
effect
detail
describe
mechanism
behind
its
occurrence.
identify
boundaries
plane
coupling
coefficient
varying
control
values
neurons.
has
previously
been
used
as
node
spiking
neural
networks
training
via
spike-timing-dependent
plasticity
due
to
lack
an
effect.
detection
range
parameters
makes
potential
application
STDP
possible.
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2024,
Номер
unknown
Опубликована: Фев. 1, 2024
SUMMARY
Synaptic
plasticities,
such
as
long-term
potentiation
(LTP)
and
depression
(LTD),
tune
synaptic
efficacy
are
essential
for
learning
memory.
Current
studies
of
plasticity
in
humans
limited
by
a
lack
adequate
human
models.
Here,
we
modeled
the
thalamocortical
system
fusing
induced
pluripotent
stem
cell–derived
thalamic
cortical
organoids.
Single-nucleus
RNA-sequencing
revealed
that
most
cells
mature
organoids
were
glutamatergic
neurons.
When
fused
to
form
assembloids,
formed
reciprocal
long-range
axonal
projections
synapses
detectable
light
electron
microscopy,
respectively.
Using
whole-cell
patch-clamp
electrophysiology
two-photon
imaging,
characterized
transmission.
Thalamocortical
corticothalamic
displayed
short-term
analogous
animal
LTP
LTD
reliably
at
both
synapses;
however,
their
mechanisms
differed
from
those
previously
described
rodents.
Thus,
assembloids
provide
model
exploring
circuits.
Highlights
Human
consist
mostly
projection
synapses.
Synapses
functional
undergo
resembling
Long-term
reveal
distinct
eTOC
often
used
diseases
with
pathology;
few
have
examined
function
via
single-cell
or
single-synapse
recordings.
Patton
et
al.
into
examine
transmission
short-
GRAPHICAL
ABSTRACT
Non-invasive
brain
stimulation
techniques
have
the
potential
to
improve
memory
functions.
However,
results
so
far
been
relatively
modest
and
time-consuming.
Here,
we
implemented
a
novel
3-minute
combination
of
personalized
repetitive
transcranial
magnetic
(intermittent
theta
burst-iTBS)
coupled
with
simultaneous
application
gamma
alternating
current
(γtACS)
over
precuneus,
area
connected
hippocampus,
modulate
long
term
in
healthy
subjects.
Only
dual
electromagnetic
precuneus
produced
consistent
increase
long-term
associative
as
compared
iTBS
alone
sham
conditions
sample
volunteers.
The
effects
were
replicated
another
independent
sample,
which
increased
was
retained
for
up
one
week.
Moreover,
oscillations
precuneus-hippocampus
functional
connectivity
through
white
matter
tracts
linking
temporal
lobe.
These
findings
show
that
may
lead
neuronal
assemblies
state
favorable
enhance
plasticity
identify
key
involved
formation.
Personalized
network
represent
new
powerful
approach
enhancing
functions
several
clinical
conditions.
Non-invasive
brain
stimulation
techniques
have
the
potential
to
improve
memory
functions.
However,
results
so
far
been
relatively
modest
and
time-consuming.
Here,
we
implemented
a
novel
3-minute
combination
of
personalized
repetitive
transcranial
magnetic
(intermittent
theta
burst-iTBS)
coupled
with
simultaneous
application
gamma
alternating
current
(γtACS)
over
precuneus,
area
connected
hippocampus,
modulate
long
term
in
healthy
subjects.
Only
dual
electromagnetic
precuneus
produced
consistent
increase
long-term
associative
as
compared
iTBS
alone
sham
conditions
sample
volunteers.
The
effects
were
replicated
another
independent
sample,
which
increased
was
retained
for
up
one
week.
Moreover,
oscillations
precuneus-hippocampus
functional
connectivity
through
white
matter
tracts
linking
temporal
lobe.
These
findings
show
that
may
lead
neuronal
assemblies
state
favorable
enhance
plasticity
identify
key
involved
formation.
Personalized
network
represent
new
powerful
approach
enhancing
functions
several
clinical
conditions.
In
the
textbook
view,
NMDA
receptors
(NMDARs)
act
as
coincidence
detectors
in
Hebbian
plasticity
by
fluxing
Ca
2+
when
simultaneously
depolarized
and
glutamate
bound.
detection
requires
that
NMDARs
be
located
postsynaptically,
but
enigmatic
presynaptic
(preNMDARs)
also
exist.
It
is
known
preNMDARs
regulate
neurotransmitter
release,
precisely
how
remains
poorly
understood.
Emerging
evidence
suggest
can
signal
non-ionotropically,
without
need
for
flux.
At
synapses
between
developing
visual
cortex
layer-5
(L5)
pyramidal
cells
(PCs),
rely
on
Mg
Rab3-interacting
molecule
1αβ
(RIM1αβ)
to
evoked
release
during
periods
of
high-frequency
firing,
they
non-ionotropically
via
c-Jun
N-terminal
kinase
2
(JNK2)
spontaneous
regardless
frequency.
same
synapses,
timing-
dependent
long-term
depression
(tLTD)
depends
not
We
therefore
tested
if
tLTD
relies
non-ionotropic
preNMDAR
signaling.
found
at
L5
PC→PC
was
abolished
pre-
postsynaptic
NMDAR
deletion,
cementing
view
preNMDARs.
agreement
with
signaling,
prevailed
after
channel
pore
blockade
MK-801,
unlike
tLTP.
Homozygous
RIM1αβ
deletion
did
affect
tLTD,
wash-in
JNK2
blocker
SP600125
tLTD.
Consistent
a
JNK2,
peptide
blocking
interaction
Syntaxin-1a
(STX1a)
loaded
Finally,
low-frequency
blocked
nor
7-CK,
non-competitive
antagonist
co-agonist
site.
conclude
neocortical
signaling
JNK2/STX1a.
Our
study
brings
closure
long-standing
controversy
surrounding
highlights
ionotropic
needs
reassessed.
Communications Biology,
Год журнала:
2025,
Номер
8(1)
Опубликована: Май 12, 2025
Cerebellar
Golgi
cells
(GoCs),
segregate
parallel
fiber
(pf),
and
mossy
(mf)
inputs
on
apical
basal
dendrites.
Computational
modeling
predicted
that
this
anatomical
arrangement,
coupled
with
a
specific
ionic
channel
localization,
could
be
instrumental
to
drive
STDP
at
mf-GoC
synapses.
Here,
we
test
hypothesis
GoC
patch-clamp
recordings
in
acute
mouse
cerebellar
slices.
Repeated
mf-pf
pairing
the
theta-band
within
±
50
ms
time
window
induces
anti-symmetric
Hebbian-STDP,
spike-timing
long-term
potentiation
or
depression
(st-LTP
st-LTD)
occurring
when
action
potentials
(APs)
elicited
by
pf
stimulation
follow
precede
activation
of
mf
synapses,
respectively.
Mf-GoC
induction
requires
AP
backpropagation
from
dendrites,
NMDA
receptor
intracellular
calcium
changes.
Importantly,
is
inverted
inhibitory
control.
Thus,
experimental
evidence
confirms
extends
model
predictions
suggesting
can
bind
molecular
layer
granular
activity,
regulating
computation
learning.
Abstract
In
the
textbook
view,
NMDA
receptors
(NMDARs)
act
as
coincidence
detectors
in
Hebbian
plasticity
by
fluxing
Ca2+
when
simultaneously
depolarized
and
glutamate
bound.
detection
requires
that
NMDARs
be
located
postsynaptically,
but
enigmatic
presynaptic
(preNMDARs)
also
exist.
It
is
known
preNMDARs
regulate
neurotransmitter
release,
precisely
how
remains
poorly
understood.
Emerging
evidence
suggest
can
signal
non-ionotropically,
without
need
for
flux.
At
synapses
between
developing
visual
cortex
layer-5
(L5)
pyramidal
cells
(PCs),
rely
on
Mg2+
Rab3-interacting
molecule
1αβ
(RIM1αβ)
to
evoked
release
during
periods
of
high-frequency
firing,
they
non-ionotropically
via
c-Jun
N-terminal
kinase
2
(JNK2)
spontaneous
regardless
frequency.
same
synapses,
timing-dependent
long-term
depression
(tLTD)
depends
not
We
therefore
tested
if
tLTD
relies
non-ionotropic
preNMDAR
signaling.
found
at
L5
PC→PC
was
abolished
pre-
postsynaptic
NMDAR
deletion,
cementing
view
preNMDARs.
agreement
with
signaling,
prevailed
after
channel
pore
blockade
MK-801,
unlike
tLTP.
Homozygous
RIM1αβ
deletion
did
affect
tLTD,
wash-in
JNK2
blocker
SP600125
tLTD.
Consistent
a
JNK2,
peptide
blocking
interaction
Syntaxin-1a
(STX1a)
loaded
Finally,
low-frequency
blocked
nor
7-CK,
non-competitive
antagonist
co-agonist
site.
conclude
neocortical
signaling
JNK2/STX1a.
Our
study
brings
closure
long-standing
controversy
surrounding
highlights
ionotropic
needs
reassessed.
Communications Biology,
Год журнала:
2024,
Номер
7(1)
Опубликована: Май 9, 2024
Spatio-temporal
activity
patterns
have
been
observed
in
a
variety
of
brain
areas
spontaneous
activity,
prior
to
or
during
action,
response
stimuli.
Biological
mechanisms
endowing
neurons
with
the
ability
distinguish
between
different
sequences
remain
largely
unknown.
Learning
spikes
raises
multiple
challenges,
such
as
maintaining
memory
spike
history
and
discriminating
partially
overlapping
sequences.
Here,
we
show
that
anti-Hebbian
spike-timing
dependent
plasticity
(STDP),
at
cortico-striatal
synapses,
can
naturally
lead
learning
We
design
spiking
model
striatal
output
neuron
receiving
defined
sequential
input
from
fixed
set
cortical
neurons.
use
simple
synaptic
rule
combines
STDP
non-associative
potentiation
for
subset
presented
called
rewarded
patterns.
study
discriminate
non-rewarded
by
firing
only
after
presentation
pattern.
In
particular,
two
biological
properties
networks,
latency
collateral
inhibition,
contribute
an
increase
accuracy,
allowing
better
discrimination
These
results
suggest
may
serve
substrate
spikes.
Proceedings of the Japan Academy Series B,
Год журнала:
2023,
Номер
99(8), С. 254 - 305
Опубликована: Окт. 10, 2023
Recent
research
extends
our
understanding
of
brain
processes
beyond
just
action
potentials
and
chemical
transmissions
within
neural
circuits,
emphasizing
the
mechanical
forces
generated
by
excitatory
synapses
on
dendritic
spines
to
modulate
presynaptic
function.
From
in
vivo
vitro
studies,
we
outline
five
central
principles
synaptic
mechanics
function:
P1:
Stability
-
Underpinning
integral
relationship
between
structure
function
spine
synapses.
P2:
Extrinsic
dynamics
Highlighting
synapse-selective
structural
plasticity
which
plays
a
crucial
role
Hebbian
associative
learning,
distinct
from
pathway-selective
long-term
potentiation
(LTP)
depression
(LTD).
P3:
Neuromodulation
Analyzing
G-protein-coupled
receptors,
particularly
dopamine
time-sensitive
modulation
learning
frameworks
such
as
Pavlovian
classical
conditioning
Thorndike's
reinforcement
(RL).
P4:
Instability
Addressing
intrinsic
memory
management
during
continual
spotlighting
their
"spine
dysgenesis"
associated
with
mental
disorders.
P5:
Mechanics
Exploring
how
influence
both
sides
establish
traces
short-
memory,
thereby
aiding
integration
functions.
We
also
delve
into
historical
background
foresee
impending
challenges.
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2024,
Номер
unknown
Опубликована: Фев. 1, 2024
Abstract
Memory
has
been
extensively
studied
at
the
behavioural
as
well
cellular
level.
Spike
timing
dependent
plasticity
(STDP)
is
associated
with
N-methyl-D-aspartate
(NMDA)
receptor
activation
and
widely
accepted
to
be
essential
for
long-term
memory.
However,
experimental
evidence
remains
sparse,
probably
due
required
complex
combination
of
functional
readouts.
Recent
work
showed
that
in-vitro
cortical
networks
memorize
predict
inputs.
The
initial
dependency
prediction
on
short-term
memory
decreased
during
formation
traces.
Here,
we
stimulated
investigate
under
control
conditions,
or
NMDA
block.
anatagonist
2-amino-5-phosphonovaleric
acid
(APV)
a
concentration
did
not
significantly
reduce
network
excitability,
but
impede
trace
formation.
In
APV-treated
cultures
stimuli
persisted,
they
were
still
able
predict.
contrast
cultures,
remained
fully
This
confirms
traces
supports
notion
that,
learn
stimulus,
starts
contribute
their
predictive
capability.