Waiting for a sign? Researchers find potential brain 'switch' for new behavior

Brain diagram. Credit: dwp.gov.uk

You're standing near an airport luggage carousel and your bag emerges on the conveyor belt, prompting you to spring into action. How does your brain make the shift from passively waiting to taking action when your bag appears?

A new study from investigators at the University of Michigan and Eli Lilly may reveal the brain's "switch" for new behavior. They measured levels of a neurotransmitter called acetylcholine, which is involved in attention and memory, while rats monitored a screen for a signal. At the end of each trial, the rat had to indicate if a signal had occurred.

Researchers noticed that if a signal occurred after a long period of monitoring or "non-signal" processing, there was a spike in acetylcholine in the rat's right . No such spike occurred for another signal occurring shortly afterwards.

"In other words, the increase in acetylcholine seemed to activate or 'switch on' the response to the signal, and to be unnecessary if that response was already activated," said Cindy Lustig, one of the study's senior authors and an associate professor in the U-M Department of Psychology.

The researchers repeated the study in humans using (fMRI), which measures brain activity, and also found a short increase in right prefrontal cortex activity for the first signal in a series.

To connect the findings between rats and humans, they measured changes in , similar to the changes that produce the fMRI signal, in the brains of rats performing the task.

They again found a response in the right prefrontal cortex that only occurred for the first signal in a series. A follow-up experiment showed that direct stimulation of using drugs that target acetylcholine receptors could likewise produce these changes in oxygen.

Together, the studies' results provide some of the most direct evidence, so far, linking a specific neurotransmitter response to changes in in humans. The findings could guide the development of better treatments for disorders in which people have difficulty switching out of current behaviors and activating new ones. Repetitive behaviors associated with obsessive-compulsive disorder and autism are the most obvious examples, and related mechanisms may underlie problems with preservative behavior in schizophrenia, dementia and aging.

The findings appear in the current issue of Journal of Neuroscience.

add to favorites email to friend print save as pdf

Related Stories

Babies show visual consciousness at five months

Apr 19, 2013

(Medical Xpress)—A new study by scientists in France and Denmark has identified a neurological marker in the brain of babies as young as five months that is associated with visual consciousness, or the ...

Recommended for you

Omega-3 fatty acids and vitamin D may control brain serotonin

16 hours ago

Although essential marine omega-3 fatty acids and vitamin D have been shown to improve cognitive function and behavior in the context of certain brain disorders, the underlying mechanism has been unclear. In a new paper published ...

Researchers develop method for mapping neuron clusters

19 hours ago

A team of scientists has developed a method for identifying clusters of neurons that work in concert to guide the behavior. Their findings, which appear in the journal Neuron, address a long-standing mystery about the or ...

One brain area, two planning strategies

22 hours ago

Ready to strike, the spear fisherman holds his spear above the water surface. He aims at the fish. But he is misled by the view: Due to the refraction of light on the surface, he does not see the actual location ...

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.