bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2024,
Номер
unknown
Опубликована: Ноя. 9, 2024
Summary
Every
neuron
contains
the
same
genomic
information
but
its
complement
of
proteins
is
product
countless
neuron-specific
steps
including
pre-mRNA
splicing.
Despite
advances
in
RNA
sequencing
techniques,
splicing
biases
that
favor
one
isoform
over
another
are
largely
inscrutable
live
neurons
situ
.
Here,
Drosophila
,
we
developed
bichromatic
fluorescent
reporters
to
investigate
alternate
cacophony
–
a
gene
codes
pore-forming
α
1
-subunit
primary
neuronal
voltage-gated
Ca
2+
channel
(VGCC).
These
reveal
pattern
exon
biases,
stereotypical
differences
between
neurotransmitter
type
and
ostensibly
function.
Information
about
individual
vivo
provides
clues
role
VGCC
motifs
those
context
local
circuits.
The
application
this
technology
large
such
as
precedence
for
effective
exon-reporter
design
other
genes.
Journal of Neuroscience,
Год журнала:
2023,
Номер
43(25), С. 4598 - 4611
Опубликована: Май 23, 2023
Neurons
exhibit
a
striking
degree
of
functional
diversity,
each
one
tuned
to
the
needs
circuitry
in
which
it
is
embedded.
A
fundamental
dichotomy
occurs
activity
patterns,
with
some
neurons
firing
at
relatively
constant
"tonic"
rate,
while
others
fire
bursts,
"phasic"
pattern.
Synapses
formed
by
tonic
versus
phasic
are
also
functionally
differentiated,
yet
bases
their
distinctive
properties
remain
enigmatic.
major
challenge
toward
illuminating
synaptic
differences
between
and
difficulty
isolating
physiological
properties.
At
Drosophila
neuromuscular
junction,
most
muscle
fibers
coinnervated
two
motor
neurons:
"MN-Ib"
"MN-Is."
Here,
we
used
selective
expression
newly
developed
botulinum
neurotoxin
transgene
silence
or
larvae
either
sex.
This
approach
highlighted
neurotransmitter
release
properties,
including
probability,
short-term
plasticity,
vesicle
pools.
Furthermore,
Ca2+
imaging
demonstrated
∼2-fold
greater
influx
neuron
sites
relative
tonic,
along
an
enhanced
coupling.
Finally,
confocal
super-resolution
revealed
that
organized
more
compact
arrangement,
stoichiometry
voltage-gated
channels
other
active
zone
scaffolds.
These
data
suggest
distinctions
nano-architecture
collaborate
differentially
tune
glutamate
subtypes.SIGNIFICANCE
STATEMENT
"Tonic"
neuronal
subtypes,
based
on
differential
common
across
many
nervous
systems.
Using
recently
selectively
transmission
from
these
neurons,
reveal
specialized
structural
distinguish
neurons.
study
provides
important
insights
into
how
input-specific
diversity
achieved,
could
have
implications
for
neurologic
disorders
involve
changes
function.
Proceedings of the National Academy of Sciences,
Год журнала:
2023,
Номер
120(51)
Опубликована: Дек. 14, 2023
When
threatened
by
dangerous
or
harmful
stimuli,
animals
engage
in
diverse
forms
of
rapid
escape
behaviors.
In
Drosophila
larvae,
one
type
response
involves
C-shaped
bending
and
lateral
rolling
followed
forward
crawling.
The
sensory
circuitry
that
promotes
larval
has
been
extensively
characterized;
however,
the
motor
programs
underlying
are
unknown.
Here,
we
characterize
neuromuscular
basis
behavior.
We
used
high-speed,
volumetric,
Swept
Confocally
Aligned
Planar
Excitation
(SCAPE)
microscopy
to
image
muscle
activity
during
rolling.
Unlike
sequential
peristaltic
contractions
progress
from
segment
backward
crawling,
progresses
circumferentially
propose
progression
muscular
contraction
around
larva's
circumference
results
a
transient
misalignment
between
weight
ground
support
forces,
which
generates
torque
induces
stabilizing
body
rotation.
Therefore,
successive
cycles
slight
reactive
aligning
rotation
lead
continuous
motion.
Supporting
our
biomechanical
model,
found
disrupting
groups
undergoing
circumferential
leads
defects.
use
EM
connectome
data
identify
premotor
connectivity
patterns
could
drive
behavior
perform
neural
silencing
approaches
demonstrate
crucial
role
group
glutamatergic
neurons
Our
reveal
body-wide
putative
circuit
organization
for
execution
response.
Synaptic
heterogeneity
is
a
hallmark
of
nervous
systems
that
enables
complex
and
adaptable
communication
in
neural
circuits.
To
understand
circuit
function,
it
thus
critical
to
determine
the
factors
contribute
functional
diversity
synapses.
We
investigated
contributions
voltage-gated
calcium
channel
(VGCC)
abundance,
spatial
organization,
subunit
composition
synapse
among
between
synapses
formed
by
two
closely
related
Drosophila
glutamatergic
motor
neurons
with
distinct
neurotransmitter
release
probabilities
(P
r
).
Surprisingly,
VGCC
levels
are
highly
predictive
heterogeneous
P
individual
either
low-
or
high-P
inputs,
but
not
inputs.
find
same
number
VGCCs
more
densely
organized
at
synapses,
consistent
tighter
VGCC-synaptic
vesicle
coupling.
generated
endogenously
tagged
lines
investigate
subunits
vivo
found
α2δ–3
Straightjacket
along
CAST/ELKS
active
zone
(AZ)
protein
Bruchpilot,
both
key
regulators
VGCCs,
less
abundant
yet
positively
correlate
input.
Consistently,
Bruchpilot
dynamically
increased
across
AZs
inputs
when
potentiated
maintain
stable
following
glutamate
receptor
inhibition.
Together,
these
findings
suggest
model
which
AZ
abundance
intersects
input-specific
molecular
organization
shape
bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2025,
Номер
unknown
Опубликована: Фев. 3, 2025
Abstract
Synapse
formation
requires
the
gradual
accumulation
of
cytomatrix
proteins
and
voltage-gated
Ca
2+
channels
(VDCCs)
at
presynaptic
active
zones
(AZs)
to
support
neurotransmitter
release.
To
correlate
AZ
maturation
with
synaptic
output,
quantal
imaging
was
performed
serially
imaged
time-stamped
Drosophila
synapses.
Evoked
release
strength
correlated
strongly
age
late
scaffolds,
while
immature
sites
lacking
VDCC
supported
spontaneous
examine
how
neuronal
activity
regulates
protein
accumulation,
effects
disruptions
SV
fusion
or
action
potential
generation
were
analyzed.
Decreasing
reduced
seeding
caused
hyperaccumulation
material
existing
AZs.
Although
enlarged
AZs
are
also
observed
in
rab3
mutants,
reduction
acted
through
an
independent
mechanism
that
required
postsynaptic
glutamate
receptor-dependent
signaling.
Together,
these
data
indicate
state
sets
distinct
modes
output
strength,
shaping
both
number
size
across
development.
Synaptic
strength
can
vary
greatly
between
synapses.
Optical
quantal
analysis
at
Drosophila
glutamatergic
motor
neuron
synapses
shows
that
short-term
plasticity
also
varies
synapses,
even
those
made
by
an
individual
neuron.
Strong
and
weak
are
randomly
distributed
in
the
nerve
terminal,
as
facilitating
depressing
Although
exhibit
highly
heterogeneous
basal
low-action
potential
firing
frequency
undergo
varied
when
increases,
overall
distribution
of
across
remains
remarkably
constant
due
to
a
balance
number
facilitate
versus
depress
their
degree
synaptic
weight.
Constancy
transmitter
release
ensure
robustness
changing
behavioral
conditions.
Journal of Neuroscience,
Год журнала:
2024,
Номер
unknown, С. e1077232024 - e1077232024
Опубликована: Март 12, 2024
Cytoplasmic
protein
tyrosine
phosphatase
(PTP)
non-receptor
type
11
(PTPN11)
and
Drosophila
homolog
Corkscrew
(Csw)
regulate
the
mitogen-activated
kinase
(MAPK)
pathway
via
a
conserved
autoinhibitory
mechanism.
Disease
causing
loss-of-function
(LoF)
gain-of-function
(GoF)
mutations
both
disrupt
this
autoinhibition
to
potentiate
MAPK
signaling.
At
neuromuscular
junction
(NMJ)
glutamatergic
synapse,
LoF/GoF
elevate
transmission
strength
reduce
activity-dependent
synaptic
depression.
In
sexes
of
mutations,
vesicles
(SV)
colocalized
Synapsin
phosphoprotein
tether
is
highly
elevated
at
rest,
but
quickly
reduced
with
stimulation,
suggesting
larger
SV
reserve
pool
greatly
heightened
recruitment.
Transmission
electron
microscopy
mutants
reveals
an
number
SVs
clustered
presynaptic
active
zones,
that
increased
vesicle
availability
causative
for
neurotransmission.
Direct
neuron-targeted
extracellular
signal-regulated
(ERK)
GoF
phenocopies
local
MAPK/ERK
signaling
in
mutants,
confirming
regulatory
loss
blocks
elevation
PTPN11
ERK
mutants.
However,
csw
null
cannot
be
rescued
by
wildtype
Csw
neurons:
neurotransmission
only
expressing
neurons
glia
simultaneously.
Nevertheless,
targeted
either
or
alone
recapitulates
Thus,
PTPN11/Csw
cell
sufficient
upregulate
function,
dual
requirement
necessary
Taken
together,
we
conclude
acts
glia,
LoF
similarly
upregulating
enhance
Synapsin-mediated
trafficking.
Significance
statement
Noonan
syndrome
(NS)
is,
far,
most
common
RASopathy;
group
clinically-classified
genetic
syndromes
caused
alterations:
it
affects
1
every
1000-2000
people.
Patients
present
cognitive
deficits
mutations;
basis
NS,
resulting
NS
multiple
lentigines
(NSML).
We
find
NS/NSML
patient-derived
as
well
corkscrew
all
increase
signaling,
turnover,
release
sites.
Surprisingly,
PTPN11/corkscrew
required
control
strength.
These
findings
suggest
disease
interventions
manipulating
trafficking
mechanisms,
therapeutic
strategies
targeting
neurons.