- A new study from the Salk
Institute for Biological Studies
reveals promising details about
the neuroscience of itching,
and all they had to do
was engineer lab mice
with an endless, maddening itch.
(electronic music)
Under the leadership of
biologist Steeve Bourane,
the team of researchers investigated
the two types of itching.
There's mechanical itching,
and then there's chemical itching.
For the mechanical itch,
think of a feather
ghosting across your skin.
It stirs your body's tiny vellus hairs.
Chemical itching, on the other
hand, stems from allergens.
Both forms of the sensation aid us
in our defense against parasitic attacks.
Mechanical itch tries
to warn you that, hey,
a mosquito's landed on your arm,
while chemical itch warns
you that a chemical irritant
is present in the skin
but could potentially be scratched away.
So, as with pain, itching is important.
Stubbing your toe sucks,
insect bites suck,
but these are necessary biological alarms.
A real problem emerges, however,
when the alarms go off for no reason,
and that's the realm of chronic
pain and chronic itching.
And if chronic itching
doesn't sound all that bad,
just imagine a scalp itch so horrendous
that you scratch through
your skull and hit brain.
Yeah, that actually happened once
according to a 2002 case report
published in the journal Pain.
In order to treat chronic itching,
we have to better understand
the neural pathways involved.
Scientists identified the
specific chemical itching neurons
back in 2009, and thanks
to this latest study,
we now know neural
transmitter neuropeptide Y,
that's NPY for short,
handles the mechanical itch.
But the researchers weren't
sure exactly how it worked,
so they bred mice without NPY
to see how they'd function.
As it turned out, and I know
this sounds kind of horrible,
the mice scratched themselves constantly
following mechanical itch stimulation.
NPY, as it turned out, was
a stop button for itching.
Without it, there's no
slamming on the brakes
as you barrel down scratch mountain.
Scientists still have a lot of work to do
as we unravel the mystery of itching,
but the newly discovered pathway
brings us one step closer
to effective chronic
mechanical itch treatments
because no one should have to
scratch down to their brain ever again.
So, what's your take on this study?
Let us know, and, hey, scratch your itch
for more weird, wonderful science over at
Now.HowStuffWorks.com.
