I'm a neuroscientist and I'm the
co-founder of backyard brains and our
mission is to train the next generation
of neuro scientists by taking graduate
level neuroscience research equipment
and making it available for kids in
middle schools and high schools and so
when we go into the classroom one way to
get them thinking about the brain which
is very complex is to ask them a very
simple question about neuroscience and
that is what has a brain and we ask that
students will instantly tell you that
their cat or dog has a brain and most
will say that a mouse or even a small
insect has a brain but almost nobody
says that a plant or a tree or shrub has
a brain and so when you push in in
because this could actually help
describe a little bit how the brain
actually functions so you push and say
well what is it that that makes living
things have brains versus not and often
they'll come back with the
classification that things that move
tend to have brains and that's
absolutely correct I mean our nervous
system evolved because it is electrical
it's fast so we can quickly respond to
stimuli in the world and move if we need
to but you can go back and push back on
the students you say well you know you
say that plants don't have brains but
plants do move anyone who's grown a
plant has noticed that the plant will
move and face the Sun but they'll say
but that's a slow movement you know that
doesn't count that could be a chemical
process but what about fast moving
plants now in 1760 Arthur Dobbs the
royal governor of North Carolina made a
pretty fascinating discovery in the
swamps behind his house he found a plant
that would spring shut every time a bug
would fall in between it and he called
this plant the flytrap and within a
decade it made its way over to Europe
where eventually the great Charles
Darwin got to study his plant and this
plant absolutely blew him away he called
the most wonderful plant in the world
this is a plant that was an evolutionary
wonder this is a plant that moves
quickly which is rare as the plant
that's carnivorous which is also rare
it's in the same plant but I'm here
today to tell you that's not even the
coolest thing about this plan the
coolest thing is that the plant can
count so in order to show that we have
to get some vocabulary out of the way so
I'm going to do what we do in the
classroom with students we're going to
do a Lex pyramid on electrophysiology
which is the recording of the body's
electrical signals either coming from
neurons or from muscles and I'm put some
electrodes here on my wrists and as I
hook them up we're going to be able to
see a signal on the screen here and this
signal may be familiar to you is called
the EKG or the electrocardiogram and
this is coming from neurons in my heart
that are firing what's called active
potentials potential meaning voltage and
action meaning it moves quickly up and
down which causes my heart to fire which
that causes the signal that you see here
and so I want you to remember the shape
of what we're we looking at right here
because this is going to be important so
this is a way that the brain encodes
information in the form of an action
potential so now let's turn to some
plants so I'm gonna first introduce you
to the mimosa not the drink but the
mimosa pudica and this is a plant that's
found in Central America and South
America and has behaviors and the first
behavior I'm going to show you is if I
touch the leaves here you get to see
that the leaves tend to curl up and then
the second behavior is if I tap the leaf
the entire branch seems to fall down so
why does it do that it's not really
known to science one of the reasons why
could be that it scares away insects or
it looks less appealing to herbivores
but how does it do that now that's
interesting we can do an experiment to
find out so what we're going to do now
just like I recorded the the electrical
potential from my body we're gonna
record the electrical potential from
this plant right here this mimosa and so
what we're going to do is I've got a
wire wrapped around the the stem and
I've got the ground electrode we're in
the ground so let's go engine earring
joke all right so the
alright so I'm gonna go ahead and tap
the leaf here and I want you to look at
the electrical recording that we're
gonna see inside the plant oh it's so
big I got to scale it down alright so
what is that that is an action potential
that's happening inside the plant why
was it happening because it wanted to
move right and so when I hit the touch
receptors it set a voltage all the way
down to the end of the stem which caused
to move and now in our mARMS
we would move our muscles but in the
plant doesn't have muscles what it has
are water inside the cells and with a
voltage hit it opens up releases the
water changes the shape of the cells and
the leaf falls ok so here we see an
action potential encoding information to
move alright but can it do more so let's
gonna find out we're gonna go to our
good friend the Venus flytrap here and
we're gonna take a look at what happens
inside the leaf when we touch when a fly
lands on here so I'm gonna pretend to be
a fly right now and I here's my venus
flytrap and inside the leaf you're gonna
notice that there are three little hairs
here and those are trigger hairs and so
when a fly lands I'm going to touch one
of the hairs right now ready 1 2 3 what
do we get we get a beautiful action
potential however the flytrap doesn't
close and to understand why that is we
need to know a little bit more about the
behavior of the flytrap number one is
that it takes a long time to open the
traps back up you know about you know 24
to 48 hours if there's no fly inside of
it and so it takes a lot of energy and
number two it doesn't need to eat that
many flies throughout the year it only
needs to need a handful gets most of its
energy from the Sun it's just trying to
replace some nutrients in the ground
with the Flies and the third thing is it
only opens then closes the traps a
handful of times until that trap dies so
therefore it wants to make really darn
sure that there's a meal inside of it
before the snap the fly trap snaps shut
so how does it do that it's the number
of seconds between successive touching
of those hairs and so the idea is that
there's a high probability if there's a
fly inside of there they're gonna be
quick together and so when it gets the
first action potential it starts
counting one two and if it gets to 20
and it doesn't
fire again that is not going to close
but if it does it within there then the
flytrap will close and we're going to go
back now I'm gonna touch the Venus flash
up again I've been talking for more than
20 seconds so we can see what happens
when I touch the hair a second time so
what do we get we get a second action
potential but again the leaf doesn't
close so now if I go back in there and
then I find my fly moving around I'm
going to be touching the leave a few
times I'm gonna go and brush it a few
times and immediately the flytrap closes
so here we're seeing the flytrap
actually doing a computation it's
determining if there's a fly inside the
trap and then it closes so let's go back
to our original question do plants have
brains well the answer is no there's no
brains in here there's not a you know no
axons no neurons it doesn't get
depressed it doesn't want to know what
the Tiger score is it doesn't have
self-actualization problems but what it
does have is something that's very
similar to us which is the ability to
communicate using electricity just uses
slightly different ions than we do but
it's actually doing the same thing so
just to show you the ubiquitous nature
of these action potentials we saw it in
the Venus flytrap we've seen an active
potential in the mimosa we've even seen
an action potential in a human now this
is the the gyro of the brain it's the
way that all information is passed and
so what we can do is we can use those X
potentials to pass information between
species of plants and so this is our
inner species plant to plant
communicator and what we've done is
we've we've created a brand new
experiment where we're going to record
the action potential from a Venus
flytrap and we're gonna send it into the
sensitive mimosa so I want you to recall
what happens when we touch the leaves of
the mosa it has touch receptors that are
sending that information back down in
the form of an action potential and so
what would happen if we took the action
potential from the Venus flytrap and
sent it into all the stems of the mimosa
we should be able to create the behavior
of the memo says without actually
touching it ourselves and so if you
allow me I'm going to go ahead and
trigger
this vamos awright now by touching on
the the hairs of the Venus flytrap so
we're going to send information about
touch from one plant to another
so there you see it so
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so I hope you learned a little bit
something about plants today and not
only that you learned that plants can be
used to help teach neuroscience and
bring along the neuro Revolution thank
you
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