Neocortex
is
classically
divided
into
distinct
areas,
each
specializing
in
different
function,
but
all
could
benefit
from
reinforcement
feedback
to
inform
and
update
local
processing.
Yet
it
remains
elusive
how
global
signals
like
reward
punishment
are
represented
cortical
computations.
Previously,
we
identified
a
neuron
type,
vasoactive
intestinal
polypeptide
(VIP)-expressing
interneurons,
auditory
cortex
that
recruited
by
behavioral
reinforcers
mediates
disinhibitory
control
inhibiting
other
inhibitory
neurons.
As
the
same
circuit
present
virtually
throughout
cortex,
wondered
whether
VIP
neurons
likewise
cortex.
We
monitored
neural
activity
dozens
of
regions
using
three-dimensional
random
access
two-photon
microscopy
fiber
photometry
while
mice
learned
an
discrimination
task.
found
during
initial
learning
produce
rapid,
cortex-wide
activation
most
interneurons.
This
recruitment
mode
showed
variations
temporal
dynamics
individual
across
areas.
Neither
weak
sensory
tuning
interneurons
visual
nor
their
arousal
state
modulation
was
fully
predictive
reinforcer
responses.
suggest
response
supports
cell-type-specific
mechanism
which
organism-level
information
about
regulates
processing
plasticity.
Annual Review of Neuroscience,
Год журнала:
2020,
Номер
43(1), С. 95 - 117
Опубликована: Фев. 20, 2020
Synaptic
plasticity,
the
activity-dependent
change
in
neuronal
connection
strength,
has
long
been
considered
an
important
component
of
learning
and
memory.
Computational
engineering
work
corroborate
power
through
directed
adjustment
weights.
Here
we
review
fundamental
elements
four
broadly
categorized
forms
synaptic
plasticity
discuss
their
functional
capabilities
limitations.
Although
standard,
correlation-based,
Hebbian
primary
focus
neuroscientists
for
decades,
it
is
inherently
limited.
Three-factor
rules
supplement
with
neuromodulation
eligibility
traces,
while
true
supervised
types
go
even
further
by
adding
objectives
instructive
signals.
Finally,
a
recently
discovered
hippocampal
form
combines
above
elements,
leaving
behind
requirement.
We
suggest
that
effort
to
determine
neural
basis
adaptive
behavior
could
benefit
from
renewed
experimental
theoretical
investigation
more
powerful
plasticity.
Cell,
Год журнала:
2020,
Номер
183(6), С. 1586 - 1599.e10
Опубликована: Ноя. 6, 2020
The
hippocampus
is
crucial
for
spatial
navigation
and
episodic
memory
formation.
Hippocampal
place
cells
exhibit
spatially
selective
activity
within
an
environment
have
been
proposed
to
form
the
neural
basis
of
a
cognitive
map
space
that
supports
these
mnemonic
functions.
However,
direct
influence
cell
on
behavior
has
not
yet
demonstrated.
Using
'all-optical'
combination
simultaneous
two-photon
calcium
imaging
optogenetics,
we
identified
selectively
activated
encoded
behaviorally
relevant
locations
in
virtual
reality
environment.
Targeted
stimulation
small
number
was
sufficient
bias
animals
during
task,
providing
causal
evidence
hippocampal
actively
support
memory.
Learning
requires
neural
adaptations
thought
to
be
mediated
by
activity-dependent
synaptic
plasticity.
A
relatively
non-standard
form
of
plasticity
driven
dendritic
calcium
spikes,
or
plateau
potentials,
has
been
reported
underlie
place
field
formation
in
rodent
hippocampal
CA1
neurons.
Here,
we
found
that
this
behavioral
timescale
(BTSP)
can
also
reshape
existing
fields
via
bidirectional
weight
changes
depend
on
the
temporal
proximity
potentials
pre-existing
fields.
When
evoked
near
an
field,
induced
less
potentiation
and
more
depression,
suggesting
BTSP
might
inversely
postsynaptic
activation.
However,
manipulations
cell
membrane
potential
computational
modeling
indicated
anti-correlation
actually
results
from
a
dependence
current
such
weak
inputs
potentiate
strong
depress.
network
model
implementing
learning
rule
suggested
enables
population
activity,
rather
than
pairwise
neuronal
correlations,
drive
experience.
