Gene blocking turns monkeys into workaholics

[Guest guest]

Gene blocking turns monkeys into workaholics

Wednesday, August 11, 2004 Posted: 6:57 PM EDT (2257 GMT)

http://www.cnn.com/2004/TECH/science/08/11/procrastinating.monkeys.reut/inde

x.html

 

 

Monkeys, like humans, " normally slack off initially in working toward a

distant goal, " says Barry Richmond of the National Institute of Mental

Health.

 

 

 

RELATED

• National Institute of Mental Health

 

WASHINGTON (Reuters) -- Procrastinating monkeys were turned into workaholics

using a gene treatment to block a key brain compound, U.S. researchers

reported on Wednesday.

 

Blocking cells from receiving dopamine made the monkeys work harder at a

task -- and they were better at it, too, the U.S. government researchers

found.

 

Dr. Barry Richmond and colleagues at the National Institute of Mental Health

used a new genetic technique to block the D2 gene.

 

" The gene makes a receptor for a key brain messenger chemical, dopamine, "

Richmond said in a statement. Dopamine is a message carrying chemical

associated with rewards, movement and a variety of other important

functions.

 

" The gene knockdown triggered a remarkable transformation in the simian work

ethic. Like many of us, monkeys normally slack off initially in working

toward a distant goal, " he added.

 

For their study, Richmond and colleague used seven rhesus monkeys. They had

to push a lever in response to visual cues on a projection screen, and got a

drop of water as a reward.

 

" They work more efficiently -- make fewer errors -- as they get closer to

being rewarded. But without the dopamine receptor, they consistently stayed

on-task and made few errors, because they could no longer learn to use

visual cues to predict how their work was going to get them a reward. "

 

Writing in the Proceedings of the National Academy of Sciences, Richmond and

colleagues said they were trying to figure out how D2 is involved in a type

of learning.

 

Humans and monkeys both use this learning, which involves looking at how

much work there is, visually, and deciding how long it will take to complete

it.

 

Monkeys and humans both tend to wait until the last possible minute to

finish up the work, and become very adept at estimating how long they have.

 

Molecular geneticist Edward Ginns created a DNA antisense agent that tricked

brain cells into turning off their D2 receptors -- which are molecular

doorways used by dopamine to get into cells.

 

Antisense involves making a kind of mirror image molecule that looks like a

strand of DNA and works to block a gene's action.

 

Although some employers might take a distinct interest in the work, the NIMH

team said they are hoping to understand mental illness.

 

" In this case, it's worth noting that the ability to associate work with

reward is disturbed in mental disorders, including schizophrenia, mood

disorders and obsessive-compulsive disorder, so our finding of the pivotal

role played by this gene and circuit may be of clinical interest, " Richmond

said.

 

" For example, people who are depressed often feel nothing is worth the work.

People with obsessive-compulsive disorder work incessantly; even when they

get rewarded they feel they must repeat the task. In mania, people will work

feverishly for rewards that aren't worth the trouble to most of us. "