5th Annual VCU 3MT® Competition, held on October 18-19, 2019.
https://scholarscompass.vcu.edu/threemt/11Transcription:
Why did I get out of bed today? What’s the point of even trying? We’ve all had days like this, where we don’t
have motivation. But what if that was
your life, every day? For ten-million
people with major depressive disorder in the US, that is a reality. And it severely impairs their ability to do
tasks of daily living. Unfortunately,
for 70% of these patients, standard antidepressants do not fix their lack of
motivation. Similarly, half of breast
cancer survivors report moderate to severe lack of motivation that will last
for 6 months after chemo treatment. This
is a major problem.
Part of the reason why we don’t have a magic pill that
treats everyone’s blues is because our mouse models of depression are
faulty. The most common test for
antidepressant activity is to see if the drug makes the mouse tread water for
longer. I don’t know about you, but I
don’t spend my days treading water, and I’m not looking for a pill that will
make me tread water longer. I want a
drug that will help patients have the motivation to go to work, to take care of
themselves.
So, what I do, is I develop a new mouse model. I give this mouse the same chemotherapy that
human cancer patients get. And I want to
see if it impacts their motivation. To
do this, I put the mice in a machine, called an operant box. And this machine has a lever. When the mouse presses the lever, he gets one
piece of candy. Each next piece of candy
costs double. Two lever presses, four
lever presses, up to over a thousand lever presses for one measly piece of
candy.
And here’s what I saw: The mice who got treated
for breast cancer chemotherapy, they gave up faster. They just lacked motivation. If we gave these same mice a bowl of mouse
candy, they ate it all. If we put them
in a running wheel, they ran as much as the placebo mice. So this means the mice weren’t fatigued or
having lack of appetite due to chemo, but that they just did not want to do the
work. Now that we have this mouse model,
we can use it to help develop new antidepressants for humans. Hopefully, we’ll be able to find something in
the mice that increases their time treading water, and also the amount of work
they’re willing to do for the candy. So
that way, our patients with major depressive disorder, or treatment resistant
depression from chemotherapy, will be able to go and live full, functional
lives.
