bioRxiv (Cold Spring Harbor Laboratory),
Год журнала:
2024,
Номер
unknown
Опубликована: Март 4, 2024
Abstract
Although
hippocampal
place
cells
replay
nonlocal
trajectories,
the
computational
function
of
these
events
remains
controversial.
One
hypothesis,
formalized
in
a
prominent
reinforcement
learning
account,
holds
that
plans
routes
to
current
goals.
However,
recent
puzzling
data
appear
contradict
this
perspective
by
showing
replayed
destinations
lag
These
results
may
support
an
alternative
hypothesis
updates
route
information
build
“cognitive
map.”
Yet
no
similar
theory
exists
formalize
view,
and
it
is
unclear
how
such
map
represented
or
what
role
plays
computing
it.
We
address
gaps
introducing
learns
candidate
goals,
before
reward
available
when
its
location
change.
Our
work
extends
planning
account
capture
general
map-building
for
replay,
reconciling
with
data,
revealing
unexpected
relationship
between
seemingly
distinct
hypotheses.
Current Biology,
Год журнала:
2022,
Номер
32(17), С. 3676 - 3689.e5
Опубликована: Июль 20, 2022
tested
humans,
rats,
and
RL
agents
on
a
novel
modular
maze
d
Humans
rats
were
remarkably
similar
in
their
choice
of
trajectories
Both
species
most
to
utilizing
SR
also
displayed
features
model-based
planning
early
trials
Episodic
memory
involves
learning
and
recalling
associations
between
items
their
spatiotemporal
context.
Those
memories
can
be
further
used
to
generate
internal
models
of
the
world
that
enable
predictions
made.
The
mechanisms
support
these
associative
predictive
aspects
are
not
yet
understood.
In
this
study,
we
an
optogenetic
manipulation
perturb
sequential
structure,
but
global
network
dynamics,
place
cells
as
rats
traversed
specific
spatial
trajectories.
This
perturbation
abolished
replay
those
trajectories
development
representations,
leading
impaired
new
optimal
during
memory-guided
navigation.
However,
cell
assembly
reactivation
reward-context
were
unaffected.
Our
results
show
a
mechanistic
dissociation
two
complementary
hippocampal
codes:
code
(through
coactivity)
sequences).
Science,
Год журнала:
2024,
Номер
383(6690), С. 1478 - 1483
Опубликована: Март 28, 2024
Experiences
need
to
be
tagged
during
learning
for
further
consolidation.
However,
neurophysiological
mechanisms
that
select
experiences
lasting
memory
are
not
known.
By
combining
large-scale
neural
recordings
in
mice
with
dimensionality
reduction
techniques,
we
observed
successive
maze
traversals
were
tracked
by
continuously
drifting
populations
of
neurons,
providing
neuronal
signatures
both
places
visited
and
events
encountered.
When
the
brain
state
changed
reward
consumption,
sharp
wave
ripples
(SPW-Rs)
occurred
on
some
trials,
their
specific
spike
content
decoded
trial
blocks
surrounded
them.
During
postexperience
sleep,
SPW-Rs
continued
replay
those
reactivated
most
frequently
waking
SPW-Rs.
Replay
awake
may
thus
provide
a
tagging
mechanism
aspects
experience
preserved
consolidated
future
use.
Progress in Neurobiology,
Год журнала:
2024,
Номер
240, С. 102653 - 102653
Опубликована: Июль 2, 2024
We
present
here
a
view
of
the
firing
patterns
hippocampal
cells
that
is
contrary,
both
functionally
and
anatomically,
to
conventional
wisdom.
argue
hippocampus
responds
efference
copies
goals
encoded
elsewhere;
it
uses
these
detect
resolve
conflict
or
interference
between
in
general.
While
can
involve
space,
do
not
encode
spatial
(or
other
special
types
of)
memory,
as
such.
also
transverse
circuits
operate
an
essentially
homogeneous
way
along
its
length.
The
apparently
different
functions
parts
(e.g.
memory
retrieval
versus
anxiety)
result
from
(situational/motivational)
inputs
on
which
those
perform
same
fundamental
computational
operations.
On
this
view,
key
role
iterative
adjustment,
via
Papez-like
circuits,
synaptic
weights
cell
assemblies
elsewhere.
Science,
Год журнала:
2025,
Номер
387(6733), С. 541 - 548
Опубликована: Янв. 30, 2025
The
mechanisms
by
which
the
brain
replays
neural
activity
sequences
remain
unknown.
Recording
from
large
ensembles
of
hippocampal
place
cells
in
freely
behaving
rats,
we
observed
that
replay
content
is
strictly
organized
over
multiple
timescales
and
governed
self-avoidance.
After
movement
cessation,
avoided
animal’s
previous
path
for
3
seconds.
Chains
self-repetition
a
shorter
timescale.
We
used
continuous
attractor
model
to
demonstrate
neuronal
fatigue
both
generates
produces
self-avoidance
timescales.
In
addition,
past
experience
became
predominant
later
into
stopping
period,
manner
requiring
cortical
input.
These
results
indicate
mechanism
generation
unexpectedly
constrains
can
be
produced
across
time.
The
predictive
nature
of
the
hippocampus
is
thought
to
be
useful
for
memory-guided
cognitive
behaviors.
Inspired
by
reinforcement
learning
literature,
this
notion
has
been
formalized
as
a
map
called
successor
representation
(SR).
SR
captures
number
observations
about
hippocampal
activity.
However,
algorithm
does
not
provide
neural
mechanism
how
such
representations
arise.
Here,
we
show
dynamics
recurrent
network
naturally
calculate
when
synaptic
weights
match
transition
probability
matrix.
Interestingly,
horizon
can
flexibly
modulated
simply
changing
gain.
We
derive
simple,
biologically
plausible
rules
learn
in
network.
test
our
model
with
realistic
inputs
and
data
recorded
during
random
foraging.
Taken
together,
results
suggest
that
more
accessible
circuits
than
previously
support
broad
range
functions.
