The Journal of Physiology,
Год журнала:
2022,
Номер
601(15), С. 3071 - 3090
Опубликована: Сен. 7, 2022
Abstract
In
the
brain,
patterns
of
neural
activity
represent
sensory
information
and
store
it
in
non‐random
synaptic
connectivity.
A
prominent
theoretical
hypothesis
states
that
assemblies,
groups
neurons
are
strongly
connected
to
each
other,
key
computational
units
underlying
perception
memory
formation.
Compatible
with
these
hypothesised
experiments
have
revealed
display
synchronous
activity,
either
spontaneously
or
upon
stimulus
presentation,
exhibit
behavioural
relevance.
While
remains
unclear
how
assemblies
form
work
has
vastly
contributed
understanding
various
interacting
mechanisms
this
process.
Here,
we
review
recent
literature
on
assembly
formation
by
categorising
involved
into
four
components:
plasticity,
symmetry
breaking,
competition
stability.
We
highlight
different
approaches
assumptions
behind
discuss
ideas
as
unit
brain.
image
Representational
drift
refers
to
the
dynamic
nature
of
neural
representations
in
brain
despite
behavior
being
seemingly
stable.
Although
has
been
observed
many
different
regions,
mechanisms
underlying
it
are
not
known.
Since
intrinsic
excitability
is
suggested
play
a
key
role
regulating
memory
allocation,
fluctuations
could
bias
reactivation
previously
stored
ensembles
and
therefore
act
as
motor
for
drift.
Here,
we
propose
rate-based
plastic
recurrent
network
with
slow
excitability.
We
first
show
that
subsequent
reactivations
ensemble
can
lead
this
ensemble.
The
model
predicts
induced
by
co-activation
active
neurons
along
high
which
leads
remodeling
weights.
Consistent
previous
experimental
works,
drifting
informative
about
its
temporal
history.
Crucially,
gradual
necessary
decoding
information
from
activity
Finally,
preserved
be
decoded
an
output
neuron
having
synapses
main
region.
Memories
are
dynamic
constructs
whose
properties
change
with
time
and
experience.
The
biological
mechanisms
underpinning
these
dynamics
remain
elusive,
particularly
concerning
how
shifts
in
the
composition
of
memory-encoding
neuronal
ensembles
influence
evolution
a
memory
over
time.
By
targeting
developmentally
distinct
subpopulations
principal
neurons,
we
discovered
that
encoding
resulted
concurrent
establishment
multiple
traces
mouse
hippocampus.
Two
were
instantiated
early-
late-born
neurons
followed
reactivation
trajectories
after
encoding.
divergent
recruitment
underpinned
gradual
reorganization
modulated
persistence
plasticity
across
learning
episodes.
Thus,
our
findings
reveal
profound
intricate
relationships
between
ensemble
progression
memories
The Journal of Physiology,
Год журнала:
2022,
Номер
601(15), С. 3071 - 3090
Опубликована: Сен. 7, 2022
Abstract
In
the
brain,
patterns
of
neural
activity
represent
sensory
information
and
store
it
in
non‐random
synaptic
connectivity.
A
prominent
theoretical
hypothesis
states
that
assemblies,
groups
neurons
are
strongly
connected
to
each
other,
key
computational
units
underlying
perception
memory
formation.
Compatible
with
these
hypothesised
experiments
have
revealed
display
synchronous
activity,
either
spontaneously
or
upon
stimulus
presentation,
exhibit
behavioural
relevance.
While
remains
unclear
how
assemblies
form
work
has
vastly
contributed
understanding
various
interacting
mechanisms
this
process.
Here,
we
review
recent
literature
on
assembly
formation
by
categorising
involved
into
four
components:
plasticity,
symmetry
breaking,
competition
stability.
We
highlight
different
approaches
assumptions
behind
discuss
ideas
as
unit
brain.
image
