In
order
to
survive,
animals
often
need
navigate
a
complex
odor
landscape
where
odors
can
exist
in
airborne
plumes.
Several
plume
properties
change
with
distance
from
the
source,
providing
potential
navigational
cues
searching
animals.
Here,
we
focus
on
intermittency,
temporal
property
that
measures
fraction
of
time
is
above
threshold
at
given
point
within
and
decreases
increasing
source.
We
sought
determine
if
mice
use
changes
intermittency
locate
an
To
do
so,
trained
discrimination
task.
establish
discriminate
samples
low
high
neural
responses
olfactory
bulb
account
for
task
performance
support
encoding.
Modulation
sniffing,
behavioral
parameter
highly
dynamic
during
odor-guided
navigation,
affects
both
outcome
representation
intermittency.
Together,
this
work
demonstrates
inform
search
more
broadly
supports
notion
mammalian
odor-based
navigation
be
guided
by
properties.
How
memories
are
used
by
the
brain
to
guide
future
action
is
poorly
understood.
In
olfactory
associative
learning
in
Drosophila,
multiple
compartments
of
mushroom
body
act
parallel
assign
a
valence
stimulus.
Here,
we
show
that
appetitive
stored
different
induce
levels
upwind
locomotion.
Using
photoactivation
screen
new
collection
split-GAL4
drivers
and
EM
connectomics,
identified
cluster
neurons
postsynaptic
output
(MBONs)
can
trigger
robust
steering.
These
UpWind
Neurons
(UpWiNs)
integrate
inhibitory
excitatory
synaptic
inputs
from
MBONs
aversive
memory
compartments,
respectively.
After
formation
memory,
UpWiNs
acquire
enhanced
response
reward-predicting
odors
as
presynaptic
MBON
undergoes
depression.
Blocking
impaired
reduced
locomotion
during
retrieval.
Photoactivation
also
increased
chance
returning
location
where
activation
was
terminated,
suggesting
an
additional
role
navigation.
Thus,
our
results
provide
insight
into
how
learned
abstract
valences
gradually
transformed
concrete
memory-driven
actions
through
divergent
convergent
networks,
neuronal
architecture
commonly
found
vertebrate
invertebrate
brains.
Journal of Comparative Physiology A,
Journal Year:
2023,
Volume and Issue:
209(4), P. 467 - 488
Published: Jan. 20, 2023
Abstract
Using
odors
to
find
food
and
mates
is
one
of
the
most
ancient
highly
conserved
behaviors.
Arthropods
from
flies
moths
crabs
use
broadly
similar
strategies
navigate
toward
odor
sources—such
as
integrating
flow
information
with
information,
comparing
concentration
across
sensors,
over
time.
Because
arthropods
share
many
homologous
brain
structures—antennal
lobes
for
processing
olfactory
mechanosensors
flow,
mushroom
bodies
(or
hemi-ellipsoid
bodies)
associative
learning,
central
complexes
navigation,
it
likely
that
these
closely
related
behaviors
are
mediated
by
neural
circuits.
However,
differences
in
types
they
seek,
physics
dispersal,
locomotion
water,
air,
on
substrates
mean
circuits
must
have
adapted
generate
a
wide
diversity
odor-seeking
In
this
review,
we
discuss
common
specializations
observed
navigation
behavior
arthropods,
review
our
current
knowledge
about
subserving
behavior.
We
propose
comparative
study
arthropod
nervous
systems
may
provide
insight
into
how
set
basic
circuit
structures
has
diversified
different
environments.
Current Biology,
Journal Year:
2024,
Volume and Issue:
34(3), P. 473 - 488.e6
Published: Jan. 4, 2024
Complex
behaviors
depend
on
the
precise
developmental
specification
of
neuronal
circuits,
but
relationship
between
genetic
programs
for
neural
development,
circuit
structure,
and
behavioral
output
is
often
unclear.
The
central
complex
(CX)
a
conserved
sensory-motor
integration
center
in
insects,
which
governs
many
higher-order
largely
derives
from
small
number
type
II
stem
cells
(NSCs).
Here,
we
show
that
Imp,
IGF-II
mRNA-binding
protein
expressed
NSCs,
plays
role
specifying
essential
components
CX
olfactory
navigation
circuitry.
We
following:
(1)
multiple
circuitry
arise
NSCs.
(2)
Manipulating
Imp
expression
NSCs
alters
morphology
these
elements,
with
most
potent
effects
neurons
targeting
ventral
layers
fan-shaped
body
(FB).
(3)
regulates
Tachykinin-expressing
FB
input
neurons.
(4)
required
establishing
proper
neuropil
structures.
(5)
Loss
abolishes
upwind
orientation
to
attractive
odor
while
leaving
locomotion
odor-evoked
regulation
movement
intact.
Taken
together,
our
findings
establish
temporally
gene
can
regulate
behavior
by
developmentally
regulating
provides
first
step
toward
dissection
its
roles
behavior.
We
consider
the
problem
of
olfactory
searches
in
a
turbulent
environment.
focus
on
agents
that
respond
solely
to
odor
stimuli,
with
no
access
spatial
perception
nor
prior
information
about
odor.
ask
whether
navigation
target
can
be
learned
robustly
within
sequential
decision
making
framework.
develop
reinforcement
learning
algorithm
using
small
set
interpretable
states
and
train
it
realistic
cues.
By
introducing
temporal
memory,
we
demonstrate
two
salient
features
traces,
discretized
few
states,
are
sufficient
learn
plume.
Performance
is
dictated
by
sparse
nature
odors.
An
optimal
memory
exists
which
ignores
blanks
plume
activates
recovery
strategy
outside
obtain
best
performance
letting
their
show
mostly
casting
cross
wind,
similar
behavior
observed
flying
insects.
The
robust
substantial
changes
plumes,
suggesting
minor
parameter
tuning
may
adapt
different
environments.
Sensory
navigation
results
from
coordinated
transitions
between
distinct
behavioral
programs.
During
chemotaxis
in
the
Drosophila
melanogaster
larva,
detection
of
positive
odor
gradients
extends
runs
while
negative
promote
stops
and
turns.
This
algorithm
represents
a
foundation
for
control
sensory
across
phyla.
In
present
work,
we
identified
an
olfactory
descending
neuron,
PDM-DN,
which
plays
pivotal
role
organization
turns
response
to
graded
changes
concentrations.
Artificial
activation
this
neuron
induces
deterministic
followed
by
initiation
turning
maneuvers
through
head
casts.
Using
electron
microscopy,
reconstructed
main
pathway
that
connects
PDM-DN
peripheral
system
pre-motor
circuit
responsible
actuation
forward
peristalsis.
Our
set
stage
detailed
mechanistic
analysis
sensorimotor
conversion
inputs
into
action
selection
perform
goal-oriented
navigation.
Current Biology,
Journal Year:
2019,
Volume and Issue:
29(10), P. 1647 - 1659.e8
Published: May 1, 2019
Studying
the
intertwined
roles
of
sensation,
experience,
and
directed
action
in
navigation
has
been
facilitated
by
development
virtual
reality
(VR)
environments
for
head-fixed
animals,
allowing
quantitative
measurements
behavior
well-controlled
conditions.
VR
long
featured
studies
Drosophila
melanogaster,
but
these
experiments
have
typically
allowed
fly
to
change
only
its
heading
a
visual
scene
not
position.
Here
we
explore
how
flies
move
two
dimensions
(2D)
using
environment
that
more
closely
captures
an
animal's
experience
during
free
behavior.
We
show
flies'
2D
interaction
with
landmarks
cannot
be
automatically
derived
from
their
orienting
under
simpler
one-dimensional
(1D)
Using
novel
paradigms,
then
demonstrate
adapt
response
optogenetically
delivered
appetitive
aversive
stimuli.
Much
like
free-walking
after
encounters
food,
exploring
respond
optogenetic
activation
sugar-sensing
neurons
initiating
local
search,
which
appears
rely
on
landmarks.
Visual
can,
however,
help
avoid
areas
where
they
aversive,
generated
heat
stimulus.
By
coupling
presence
near
specific
shapes,
elicit
selective
learned
avoidance
those
Thus,
adaptively
navigate
environments,
reliance
is
context
dependent.
These
behavioral
paradigms
set
stage
interrogation
brain
circuitry
underlying
flexible
complex
multisensory
environments.
