►
Description
Lecture on Mechanosensation in the adult hermaphrodite C. elegans. Slides: https://drive.google.com/open?id=112yk5NOCwnHgD0c2iOnYn5VJgu0M7B6L
A
Behaviors
dealing
with
this
response
to
touch
so
very
broadly
Meccano
sensation
is
the
touch,
so
a
stimulation
leads
to
motor
response.
This
is
almost
always
true
that
there's
some
kind
of
a
stimulation
which
is
then
induces
a
body
deformation
and
the
body
deformation
then
travels
through
essentially
two
pathways
and
I
referred
them:
the
sensation
and
no
c-section
so
nociception.
We
might
call
it
pain,
response
or
hardness
response.
A
They
are
in
fact
distinct.
So
sensation
would
be
something
gentle
and
say
the
worm
would
bump
up
against
an
obstacle
or
the
worm
would
pop
up
against
some
food,
whereas
nociception
might
be
due
to
say
a
predator
is
trying
to
attack
it
and
it
would
actually
recruit
different
neurons.
So
those
neurons
would
would
modulate
the
severity
of
the
response
and
which
behavior
is
selected
and
that's
why
I
have
them
down
as
two
different
pathways.
And
then
these
two
things
go
into
inter
neurons,
which
typically
are
called
the
command
neurons.
A
A
A
A
Onus
is
well
beyond
what
we
call
harsh
touch.
Gentle
touch
that
is
broken
up
into
two,
and
this
basically
could
be
an
escape,
so
wouldn't
escape
would
mean.
Is
that
none
of
the
pain
receptors
neurons
are
firing
for
gentle
touch,
but
it
bumped
into
something.
So
it
can't
continue
on
its
current
path,
or
perhaps
it's
no
hitting
other
were
something
of
that
fashion.
A
On
the
other
hand,
gentle
touch
might
also
indicate
the
presence
of
food
and
there's
a
distinct
response
called
the
foraging
response
that
is
mediated
by
dopamine
and
that
gentle
touch
is
primarily
mediated
by
cuts
to
the
nose
harvest.
Touch,
on
the
other
hand,
recruits
those
nociceptors.
That
I
was
talking
about
the
pain,
receptive,
neurons
and
they're
significantly
different
they're,
primarily
an
escape
response.
There's
no
additional
responses.
It's
you
know
parts
types.
It
is
a
get.
B
A
Of
here
something
is
wrong:
responsible,
breaking
behavior
up
for
a
state
even
further.
We
have
the
forward
to
state
response
in
the
backward
forward.
Escape
is
a
little
bit
easier
to
explain
so
I'll
focus
on
that
one
first,
and
the
reason
for
that
is
because
there's
only
really
two
neurons
that
are
recruited
for
this
one,
and
it
is
primarily
when
the
word
was
touched
in
the
posterior,
and
so
with
this
recruits.
A
For
gentle
touch
is
a
neuron
called
PLM,
and
this
is
the
direct
McKenna
sensory
neuron,
essentially
body
deformation,
activates
PLM,
then
PLM
stands
on
a
signal
to
the
inter
neurons
that
eventually
caused
the
worm
to
move
forward.
So
when
I
say
forward,
I
mean
that
the
the
vector
of
motion
moves
about
points
from
the
tail
to
the
head
and
then
when
there's
first
touch
involved,
there's
another
neuron
recruited
called
PVD
and
DVD
is
a
very
special
neuron.
A
The
head
is
rather
complex
in
terms
of
all
of
its
sensory
organs,
there's
a
number
of
different
things
going
on,
especially
around
the
mouth
and
and
what
we
might
call
the
face
and,
as
a
result,
the
backward
responses
are
a
little
bit
more
complex.
So
we
do
have
those
heads
and
cilia
the
the
organs,
the
sensory
organs
and
the
in
the
head,
which
we'll
be
talking
about
a
little
bit
later.
A
Talking
about
how
the
head
responds
to
touch,
but
then
the
the
anterior
body
itself
is
innervated
by
the
the
new
yorks
pln,
which
is
equivalent
to
the
pln
around
the
posterior,
and
then
PVD
is
so
like
I
said
and
I'll
be
saying
a
couple
times
with
a
presentation:
PVD
is
a
whole
body,
sensory
neuron
that
only
responds
to
parts
times.
It
only
really
induces
a
strong
escape
behavior
now
and
then
we
want
to
consider
a
lemon-peel
them
to
be
the
direction
of
escape
selectors.
A
Another
interesting
behavior
is
called
foraging,
and
this
is
really
where
the
the
touch
to
the
front
of
the
worm
gets
interesting.
Foraging
is
media,
but
in
your
own
called
CEP.
So
this
is
primarily
in
the
mouth
it's
radially
distributed
around
the
mouth.
There
are
several
of
them
and
the
literature
calls
it
texture
base.
A
So
what
that
means
is
that
the
worm
is
actually
capable
of
sensing
when
it,
when
it's
hitting
only
a
small
thing
like
a
bacterium,
you
compare
it
to
a
larger
thing,
like
the
barrier
say
a
barrier
like
another
worm,
for
example,
what
CEP
does
in
response
to
detecting
there's
food
in
front
of
it
is
it'll
actually
release
dopamine
extras
actively.
So
this
affects
the
whole
body
of
the
worms.
Is
this
dopamine
release,
so
this
will
increase
and
then
decreased
of
movement
speed?
A
A
Let's
know
zoom
in
a
little
bit,
so
we
talked
about
the
behaviors
of
nose
touch.
Let's
talk
about
nose
touch
in
particular,
and
the
neurons
involved
there
and
so
I'm
going
to
begin
with
what
is
also
called
noxes
types
or
harsh
types.
So
the
literature
uses
both
terms,
I
decided
to
use
both
for
that
reason,
and
so
touch
activates
a
two
neurons.
So
these
neurons
are
called
FL
TSH
and
these
are
in
the
head
of
the
word.
Fl
P
responds
both
to
the
gentle
and
harsh
type,
so
it's
a
poly
modal
neuron.
A
So
a
sh
can
do
noxious
chemicals
as
well
as
lighting
and
touching
a
bunch
of
other
things.
Flp
is
primarily
indicated
and
touched
in
as
well
as
temperature,
and
they
only
are
localized
in
the
head
and
neck.
So
this
is
where
now
their
receptive
fields
are,
so
they
do
have
some
similarities.
With
that
being
said,
there
are
in
fact,
significant
differences,
and
that's
where
we
come
to
here,
which
is
what
we
might
term
the
FLP
olq
cep
interaction.
So
it's
a
lot
of
acronyms.
These
are
three
neurons
that
are
responsible.
A
Essentially,
they
act
as
a
behavior
selection
circuit,
forehead
and
nose
touch
I
like
to
talk
a
little
bit
about
how
that
might
work.
We've
already
talked
about
the
CEP
neuron,
so
that's
a
neuron
that
detects
whether
or
not
there's
food
in
front
of
the
worm.
You
know,
LP
is
tentatively,
knows
receptive
as
well,
but
then
olq
comes
in
and
that's
another
whole
head.
Whether
or
not
the
worm
is
touching
something
with
its
mouth
and
so
you'll
see
in
the
diagram
here.
A
It
says
that
one
of
the
behaviors
is
headed
withdrawal
and
that's
Q
mediated
one
of
them.
That
is
a
dopamine
release
and
that
is
slowing
and
then
echo
P
can
handle
some
pain
responses
as
well.
The
interesting
thing
about
this
just
neural
circuit
is
that
it
acts,
and
this
is
from
a
shame
for
2015
as
a
coincidence,
detector,
and
so
what
that
means
is
that
if
a
single
neuron
is
firing
in
this
in
this
circuit,
then
a
particular
behavior
is
activated.
A
A
So
this
is
what
we
might
term
a
a
small
subset
of
a
behavioral
selection
circuit
and
that's
one
of
the
major
differences
between
a
copy
and
a
sh,
whereas
a
sh
is
primarily
indicated
in
in
pain
responses,
they're,
not
just
touch
stimuli
FLT
can
actually
be
used
to
do
more
complex
things
talking
a
little
bit
more
about
the
foraging
response
and
how
it
works.
So
the
one
question
that
we
might
ask
is:
is
it
actually
a
mechanical
response?
For
example,
perhaps
the
bacteria
released
a
chemical
and
the
chemical
is
sensed.
A
Demonstrably
not
a
chemical
response,
so,
although
the
worm
is
capable
of
moving
towards
bacteria
using
chemical
gradients,
the
foraging
response
is
demonstrably
not
chemical.
The
way
you
demonstrate
this
is
quite
interesting.
You
take
some
sterile
beats
now
various
sizes
and
these
beads
essentially
emulate
the
mechanical
forces
that
the
worm
might
encounter
if
it
wasn't
backed
hitting
bacteria
with
its
mouth
and
the
worm
still
exhibits
the
slowing
responses.
A
So,
although
the
sterile,
a
synthetic
beats
are
certainly
not
bacteria,
they're,
certainly
not
releasing
any
chemical
signals
to
indicate
that
they're
edible
the
worm
will
still
try
to
try
to
consume
them.
The
next
thing
is
it's:
a
graded
response
in
the
the
gradation
depends
on
how
to
food
deprived.
The
animal
is
so,
for
example,
a
starved
animal.
A
So
an
animal
who
hasn't
had
food
for
more
than
thirty
minutes
put
into
a
an
area
with
a
lot
of
bacteria
or
the
SRL
beads
will
in
fact
show
a
greater
response,
and
what
that
greater
response
means
is
a
significantly
more
slowing,
so
the
worm
will
move
forward
at
a
much
slower
pace
if
at
all,
it
might
actually
stop
and
animals
that
are
well-fed.
Do
not
exhibit
as
pronounced
a
slowing
behavior
then.
A
The
head
touch
so,
like
I
said
the
two
neurons
that
are
primarily
important
for
this
is
PLM
and
Neelam,
and
they
do
broadly
similar
things,
so
they
both
have
on
and
off
responses.
That
is
that
they
both
have
a
membrane
potential
change
when
the
force
is
applied
and
also
when
it
force
is
released,
they
are
created.
So
what
that
means
is
that
the
magnitude
of
the
membrane
potential
change
is
dependent
on
the
strength
of
the
input.
A
Stimulus
is
very
high
and
they're,
actually
mutually
inhibitory,
so
I'll
be
showing
a
neural
circuit
a
little
bit
later,
not
talking
about
what
that
looks
like
and
basically
the
idea
is
that,
if
peel
and
is
active,
that
might
indicate
there's
a
posterior
types
of
current
and
the
worm
has
to
escape
forward.
If
ALM
is
active,
then
that
would
be
an
interior
response
and
then
we
refer
to
skate
backwards.
A
Obviously
the
worm
cannot
escape
both
forward
and
backward
at
the
same
time,
so
they
are
in
fact
admitting
each
other
so
that
only
one
of
the
two
behaviors
is
selected
at
a
time
so
just
showing
what
this
looks
like
so
from
O'hagan
2004,
they
were
actually
able
to
do
some
some
experiments
to
record
the
neural
activity.
This
is
PLM,
they
recorded
that
ALM
was
similar
and
what
we
have
is
in
a
diagram
they
called
see.
A
The
touch
is
is
turned
on;
essentially
they
they
put
some
work,
and
then
we
see
this
membrane
potential
change
and
on
the
bottom,
is
a
an
output
current
as
well,
and
then,
when
the
touch
is
removed,
we
see
the
exact
same
manner,
brain
potential
change,
so
the
that's
the
own
off
response,
I
was
talking
about
and
then
in
the
next
diagram
over,
we
can
see
that
it
created
response.
So
the
magnitude
of
the
the
output
current
and
therefore
the
magnitude
of
the
membrane
potential
change
depends
significantly
on
the
magnitude
of
the
touch.
A
There's
another
neuron
called
AVM.
Unfortunately,
this
one
is
not
as
well
explored
as
the
others,
so
I'll
give
just
a
cursory
explanation
of
it.
Not
it
is
involved
in
a
backward
escapes
response
and
it
appears
to
directly
stimulate
the
motor
command
in
from
your
own,
so
it
actually
seems
to
be
directly
sort
of
control
in
that
behavior.
A
However,
it
does
not
inhibit
the
posterior
escape
response,
so
it
seems
my
merrily
am
anything
there
on
this
sort
of
causes
of
behavior
to
occur,
but
it
doesn't
prevent
any
other
behaviors
from
occurring
and
the
final
neuron
that
we'll
be
talking
about
here
is
PVD.
So
PVD
is
the
whole
body
pain,
sensing
neuron.
This
is
the
neuron
that
distinguishes
between
whether
the
worm
is
going
to
escape
due
to
a
gentle
touch
or
whether
it's
going
to
need
a
harsher
response
to
get
out
of
the
stimulus
as
fast
as
possible.
A
It
is
non
directional,
like
I,
said
so
pln
the
OLM
and
PVD
work
together
to
determine
number
one
which
direction
number
two.
How
much
magnitude
should
he
should
be
producing
the
response
and
PVD
is
indicated
to
my
mic-
relates
to
strength.
So
the
again
and
that
they
magnitude
bends
and
I
magnitude
of
the
escape
diagrams
they're,
a
diagram
D
when
harsh
types
is
applied
to
the
worm,
the
PP
do
neuron
has
a
strong
output
over
when
a
gentle
touches
applied.
A
Just
I
talked
about
the
organization
of
the
body
touch
for
neural
circuits,
so
I
would
love
to
be
able
to
say
this
is
how
it
works.
It's
nice
and
simple
like
this.
Unfortunately,
it's
not
quite
the
case,
but
this
is
a
fairly
good.
High-Level
review,
in
particular,
with
this
says,
is
which
neurons
are
primarily
responsible
for
each
of
the
behaviors.
So
at
the
bottom
we
have
VA
and
VB.
These
are
the
the
forward
and
backward
motor
neurons.
A
A
We
might
refer
to
these
as
the
forward
payment
interneuron,
so
these
are
responsible
for
modulating
and
controlling
the
emotion
of
the
room
and
when
it
goes
astray
backward
commanded
neuron.
So
when
it's
moving
backwards
and
then
Andre
right,
we
had
a
BB
in
PVC.
These
are
what
we
might
call
the
forward
and
internally
runs.
It
actually
caused
the
worm
to
move
forward
and
I
would
again,
like
I,
said,
love
to
say
it's
that
simple.
Unfortunately,
it
is,
and
we
tend
to
say,
ABB
is
responsible
for
moving
forward
and
that's
it.
A
A
But
what
is
certainly
true
is
that
those
neurons,
those
inter
neurons
there
on
either
left
and
right
side
are
the
ones
that
are
most
strongly
related
to
backwards
and
just
general
locomotion,
and
so
we
might
say
that
you
know
maybe
eighty
percent
of
the
responses
due
to
those
neurons,
the
exact
number
of
courses
is
up
for
a
debate.
Moving
up
again,
you
see
element,
Cleveland
and
what's
important
is
those
green
lines,
and
hopefully
you
can
see
my
cursor,
but
the
gray
lines
here
indicate
that
we
have
inhibition.
So
that
means
that
he
Cleveland
was
active.
A
Then
it
will,
you
know
and
excu.
The
attack
were
to
state
response
in
an
excitatory
signal
forward
escaped
neurons,
and
then
that
sense
we
have
the
were
not
trying
to
escape
both
forward
and
backwards
and
then
the
very
top.
We
see
the
PPD,
which
is
exciting
both
forward
and
backwards
and
again
that
square
that
nociception,
as
well
as
FLT
and
then
ibms
as
well,
is.
A
A
Principles
we
retain
from
the
previous
diagram,
for
example,
on
the
left.
You
can
see
that
a
BP
is
directly
stimulating
with
this,
particularly
F,
which
in
the
previous
diagram,
was
called
BB,
and
then
eta
is
directly
stimulating,
EB,
which
again
the
previous
paper
was
terminally,
a
psychologist
for
the
notation.
B
A
But
you'll
see
this
is
a
strongly
connected
network
of
neurons
and
we're
also
quite
interesting
as
a
B
arrows
here
indicating
chemical
synapse
and
the
dotted
dashed
lines
indicate
a
gap,
tension
and
we
might
ask
the
question:
well
what
are
all
these
connections
core,
so
Rakowski?
No,
no
2013
suggested
that
perhaps
most
of
these
connections
are
inhibitory.
So
what
this
might
mean
is
that
we
have
what
we
might
turn
a
behavior
selection,
a
circuit
and
essentially
most
of
the
connections.
A
Being
inhibitory
says
that
once
say,
20,
percenters
or
70
percent
of
the
neurons
are
inhibited,
then
the
ones
that
are
primarily
responsible
for
the
particular
behavior
like
forward
escape
our
actives
are
no
longer
be
inhibited
and
then
cause
that
behavior
to
happen,
and
so
a
lot
of
literature
does
point
to
this
as
being
a
behavior
selection
or
circuit.
However,
it
may
not
be
quite
so
simple
to
say
that
these
connections
are
inhibitory.
I'll,
show
you
why
so
there's.
A
On
as
well
in
the
in
the
responses
to
touch
so
one
particularly
interesting
study,
they
you
can
ablate
a
V
V,
so
you
take
away
that
we're
on
and
so
ABB
has
been
indicated
to
be
the
Penan
neuron
for
forward
motion.
So
if
it's
gone
radically,
the
worms
would
not
move
forward.
However,
if
you
touch
the
worm,
a
specific
law
stereotypes,
you
do
in
fact
get
forward
now.
This
isn't
as
strong
as
it
would
be.
An
AV
B
were
there,
so
it's
certainly
muted,
but
it's
still
there.
A
So
this
doesn't
exactly
lend
credence
to
the
idea
that
every
connection
there's
a
territory.
Something
I
must,
in
addition,
be
going
on
to
further
stimulate
the
forward
motor
neurons
and,
unfortunately,
you
can
simply
say
that
it's
a
VB
is
responsible
for
that.
So
open
question
then,
and
I'm
focusing
on
P
pieces.
So
how
does
PVC
and
if
you
produce
so
when
PVC
is,
is
the
interneuron
that
directly
is
connected
to
PLM
and,
as
you
recall,
PLM
was
connected
to
a
kind
of
sensor.
A
A
So,
like
I
was
saying,
KLM
and
PVE
stimulate
PVC,
quite
a
bit
of
acronyms
thrown
around
sorry
about
that
and
the
action
is
graded
and
it
certainly
initiates
this
scope
so
PVC
will
that
initiate
the
escape,
depending
on
the
strength
of
the
response
are
coming
in
from
those
upper
two
neurons,
LME
PVD.
Now
the
reason
I'm
focusing
on
this
one
is
because
it.
B
A
Provide
a
simple
and
nice
and
coherent
or
on,
and
the
reason
for
that
is
because
it
is
actually
unnecessary
for
the
escapes
response.
When
PVC
is
ablated,
you
simply
do
not
get
a
touch
response
at
all,
and
so
that's
that's
been
handy
that
that
means
the
welding
study,
the
behavior
at
PVC
in
isolation.
We
might
be
able
to
approximate
the
rest
of
the
neurons
from
the
rest
of
the
circuit,
but
we
can
look
at
how
PVC
works
and
ask
questions
that
how.
A
That
escape
responsible,
unfortunately,
as
in
many
things
that
are
competing
models,
so
one
of
the
models
is
there's
chemical
modulation
see
the
idea
that
we
may
see
somehow
modulates
that
response
directly
by
connecting
to
the
the
two
neurons,
a
VPN,
maybe
so
a
VB
being
responsible
for
at
least
a
majority
of
forward
motion
and
VB
being
responsible
for
emotions
for
a
motor
neuron
set.
So
the
idea
is
that
the
synaptic
weights
might
change
with
the
PVC
activity,
so
in
PVC
is
providing
an
input.
The
weights
between
a
VA
and
VB
are
changing
the
questionnaire.
A
The
look
that's
true.
So,
first
of
all,
what
exactly
is
changing
so
the?
What
is
it
there's
be
change
between
a
VB
and
VA
and
VB,
but
why
does
PVC
snaps
on
to
go?
So
why
is
it
that
PVC
has
to
change
the
synaptic
weights
of
both
a
VB,
then
B?
What
is
going
on
there?
And
the
next
question
is
what
is
that
mechanism
by
which
the
synaptic
weights
are
changing?
A
So
some
people
have
demonstrated
that
perhaps
the
mechanism
by
which
forward
motion
happens
at
the
gap
Junction
so
presumably
what's
happening,
is
that
the
membrane
conductivity
are
in
Latinos.
However,
there's
no
evidence
yet
that
I
found
the
producer.
It
gives
a
clear
explanation
of
how
PVCs
action
causes
any
changes
whatsoever
in
got
junction
of
chemical
tensions
there.
So
the
question
is
still
quite
open
as
to
how
that
works.
A
Another
model
that
might
be
considered
is
gap,
Junction
modulation.
So
the
idea
that
the
gap
junctions
aren't
just
stimulating
and
causing
the
neurons
to
fire,
but
also
that
somehow
they
actually,
we
were
working
together
or
work
opposite.
That's
where
some
models
come
in,
so
in
2011
a
study
was
done
and
the
suggestion
was
that
the
gap
junctions
actually
inhibit
opposite
junctions
are
more
than
just
a
leading
forward,
motion
or
estimate
awkward
motion.
It's
the
sense
that,
when
the
gap
Junction
for
emotion
is
active,
then
an
inhibitory
signal
is
also
sent
to
prevent
the
opposite
oven.
A
A
A
All
of
that
is
still
an
open
question,
especially
because
we
have
two
relatively
recent
papers
with
with
results
that
disagree
with
each
other,
and
the
final
question
we
might
ask
is
if
this
is
true,
so
if
it
is
not
primarily
a
gap,
Junction,
perhaps
PVC
does
change
membrane
conductivity,
when
why
is
it
that
a
VP
also
chemically
synapses
onto
what
is
the
purpose
of
having
the
two
different
ways
of
activating
the
same
neuron?
What
did
they
do
so?
A
The
behaviors,
though
they
do
depend
on
the
interaction
of
neurons.
So
we
can't
single
out
a
single
neuron
that
says:
if
this
neuron
isn't
there,
then
the
entire
response
is
not
going
to
happen.
Pvc
is
our
closest
candidate
to
that
in
that,
if
that
neuron
isn't
there,
then
the
state
responses
don't
happen,
but
that
still
leaves
open.
The
question
of
how
to
score
word.
Motion
occur
when
ABB
is
going
wide,
as
forward
motion
still
occur
and
so
forth.
So
we
can't
just
take
a
single
neuron
say
this.
A
Is
it,
however,
on
the
upside,
a
relatively
small
subset
of
neurons
is
in
fact
responsible
for
body
motion
attacks
responses,
so
there
are
some
302
neurons,
but
I've
only
talked
about
maybe
maximum
20
or
30.
If
you
consider
the
fact
that
they're
replicated
along
the
words
body-
and
so
it's
a
relatively
small
subset,
they
can
be
studied
more
or
less
in
isolation,
because
touch
responses
might
happen
in.
A
As
well,
most
inept
equates
in
the
body.
Command
network
may
actually
be
inhibitory,
so
Kowski
did
suggest
that.
However,
there's
the
jury
Cilla
we're
not
entirely
sure.
However,
we
also
know
that
these
weights
do
in
fact
change
so
for
one
mechanism,
for
that
is
exertion,
a
pic
dopamine,
that's
coming
out
of
the
cep
neuron,
and
this
has
a
clear
function
of
reducing
speed
during
the
foraging
behavior
we
talked
about
so
somehow
that's
depressing.
A
The
action
of
either
the
muscles
of
the
neurons
and
whether
that's
due
to
a
synaptic
weight
change-
or
perhaps
it's
just
due
to
a
change
in
membrane
potential-
is
the
question,
and
one
thing,
though,
that
that
seems
to
be
concluded.
Lisa
loopner.
Recent
literature
is
that
it
is
unlikely
that
synaptic
waves
are
constant
for
motor
controls,
but
unfortunately
it
looks
like
we
can't
just
take
a
single
synaptic
weight
set
and
say
the
is
it
uploaded
on
to
the
word
and
go
we'll
have
to
also
account
for
mechanisms
by
which
these
synaptic
weights
will
change.
A
A
B
A
A
The
synaptic
weights
are
in
fact
inhibitory,
but
also
when
they're,
not
inhibitory,
then
that
that
lack
of
inhibition
may
actually
drive
further
behavior,
and
it's
also
entirely
possible
that
the
synaptic
weights
changed
from
being
inhibitory
to
being
excitatory
when
some
of
the
neurons
are
ablated.
I'm
speculating
at
this
point,
but
certainly
there's
there's
much
more
complexity
going
on
than
just
being
able
to
say
that
you
know
this
is
an
inhibitory
connection,
I'm,
not
sure
we
can.
We
can
certainly
say
that
for
for
certain
yeah.
B
B
A
B
B
A
I
sort
of
took
on
the
interest
in
looking
into
these
escaped
responses.
That's
one
of
the
reasons
that
I
was
so
interested
in
kind
of
sensation
in
particular,
and
what
I'm
looking
into
right
now
is
actually
that
last
question
I
asked
so,
let's
head
back
to
that
slide,
which
is
the
open
question
here?
How
does
PVC
initiate
forward
escape?
So
at
the
moment
we
can
reasonably
simulate
motion
of
the
worm,
but
the
problem
that
we're
having
is
that,
although
we
can,
we
can
do
certain
things
like
slow
the
worm
down,
we
can
speed
it
up.
A
We
can
it's
body
Bend,
more
or
less,
depending
on
on
the
stimulus
that
we
provided.
We
don't
actually
have
much
evidence
to
indicate
that
any
of
the
methods
we're
using
to
do
that
are
actually
what
happens
in
the
worm,
and
so
what
I'm
focusing
on
right
now
is
exactly
this
question:
how
does
PVC
initiate
forward
escape
moving
to
the
neurons,
ABB
and
VB?