Listen to the post and follow along!
Who makes decisions?
How do we decide?
To run in fear, or hide?
Reward-based circuitry must be,
A part of our machinery!
Dr. Uchida has a lab,
At Harvard, you know, Boston, Mass,
They dive into the mouse’s brain,
Specifically the VTA.
If acronyms are scaring ya:
Ventral tegmental area.
Let’s take a look at what they did,
Examine their experiments.
At first they taught a mouse to tell,
Apart rewards based just on smell.
Sometimes a big reward, some small,
Sometimes no water came at all.
Sometimes an air puff to the face,
The mouse must differentiate.
It does – and licks more when it knows,
That water through lick port will flow.
They then recorded from some cells,
To see if they could really tell,
Which ones respond to which CS,
And which prefer reward the best.
Which cells might fire differently,
In groups or independently,
And their results – it’s no surprise,
Were elegant, I’ll summarize:
They clustered cells in groups, you see,
Type I, type II, and even III.
The types have different properties,
And different n-t-m release.
Type I spikes to rewarding cue,
More tonically spike cells Type II,
Type III cells are more limited,
And seem to be inhibited.
They optogened some channel rho,
To see how clean their data shows,
Each type of cell can be predicted,
By the n-t-m ejected.
And indeed results were clean,
Type I cells release dopamine,
And type II cells release the massive,
Wonderful! So now it’s known,
Each cell has functions of its own,
“And now,” the lab group said, “let’s show,
How they predictive error code!”
“Let’s signal that a big reward,
Is on its way, but just before,
The water comes we’ll just be fronting,
One of ten times the mouse gets nothing!”
“Oh no!” announced the type I cells,
“There’s no reward, dude, what the hell?!”
After the US time was finished,
They saw type I was quite diminished.
In contrast type II neurons went,
So crazy during punishment.
Rewarding stim plus puff of air,
The type II neurons said “Oh yeah!”
So now we know more things about,
Reward-based circuits in the mouse,
The push and pull of different types,
The dopamine and GABA life.
Come listen to Uchida speak,
He’ll have the answers that you seek.
On these experiments, and more,
Tuesday, CNCB, at four!
Uri Magaram is a first year graduate student in the UCSD Neuroscience program. He is currently rotating in the lab of Jeff Isaacson.
Cohen JY, Haesler S, Vong L, Lowell BB, Uchida N. Neuron-type-specific signals for reward and punishment in the ventral tegmental area. Nature. 2012 Jan 18;482(7383):85-8. doi: 10.1038/nature10754.