Featured Research

from universities, journals, and other organizations

Lights, chemistry, action: New method for mapping brain activity

Date:
April 10, 2013
Source:
Brookhaven National Laboratory
Summary:
Building on their history of innovative brain-imaging techniques, scientists have developed a new way to use light and chemistry to map brain activity in fully-awake, moving animals, opening a new window to the study of brain diseases.

Peter Thanos.
Credit: Image courtesy of Brookhaven National Laboratory

Building on their history of innovative brain-imaging techniques, scientists at the U.S. Department of Energy's Brookhaven National Laboratory and collaborators have developed a new way to use light and chemistry to map brain activity in fully-awake, moving animals.

The technique employs light-activated proteins to stimulate particular brain cells and positron emission tomography (PET) scans to trace the effects of that site-specific stimulation throughout the entire brain. As described in a paper published online today in the Journal of Neuroscience, the method will allow researchers to map exactly which downstream neurological pathways are activated or deactivated by stimulation of targeted brain regions, and how that brain activity correlates with particular behaviors and/or disease conditions.

"This technique gives us a new way to look at the function of specific brain cells and map which brain circuits are active in a wide range of neuropsychiatric diseases -- from depression to Parkinson's disease, neurodegenerative disorders, and drug addiction -- and also to monitor the effects of various treatments," said the paper's lead author, Panayotis (Peter) Thanos, a neuroscientist and director of the Behavioral Neuropharmacology and Neuroimaging Section -- part of the National Institute on Alcohol Abuse and Alcoholism (NIAAA) Laboratory of Neuroimaging at Brookhaven Lab -- and a professor at Stony Brook University. "Because the animals are awake and able to move during stimulation, we can also directly study how their behavior correlates with brain activity," he said.

The new brain-mapping method combines very recent advances in a field known as "optogenetics" -- the use of optics (light activation) and genetics (genetically coded light-sensitive proteins) to control the activity of individual neurons, or nerve cells -- and Brookhaven's historical development of radioactively labeled chemical tracers to track biological activity with PET scanners.

The scientists used a modified virus to deliver a light-sensitive protein to particular brain cells in rats. Genetic coding can deliver the protein to specifically targeted brain-cell receptors. Then, after stimulating those proteins with light shone through an optical fiber inserted through a tiny tube called a cannula, they monitored overall brain activity using a radiotracer known as ^18FDG, which serves as a stand-in for glucose, the body's (and brain's) main source of energy.

The unique chemistry of ^18FDG causes it to be temporarily "trapped" inside cells that are hungry for glucose -- those activated by the brain stimulation -- and remain there long enough for the detectors of a PET scanner to pick up the radioactive signal, even after the animals are anesthetized to ensure they stay still for scanning. But because the animals were awake and moving when the tracer was injected and the brain cells were being stimulated, the scans reveal what parts of the brain were activated (or deactivated) under those conditions, giving scientists important information about how those brain circuits function and correlate with the animals' behaviors.

"In this paper, we wanted to stimulate the nucleus accumbens, a key part of the brain involved in reward that is very important to understanding drug addiction," Thanos said. "We wanted to activate the cells in that area and see which brain circuits were activated and deactivated in response."

The scientists used the technique to trace activation and deactivation in number of key pathways, and confirmed their results with other analysis techniques. The method can reveal even more precise effects.

"If we want to know more about the role played by specific types of receptors -- say the dopamine D1 or D2 receptors involved in processing reward -- we could tailor the light-sensitive protein probe to specifically stimulate one or the other to tease out those effects," he said.

Another important aspect is that the technique does not require the scientists to identify in advance the regions of the brain they want to investigate, but instead provides candidate brain regions involved anywhere in the brain -- even regions not well understood.

"We look at the whole brain," Thanos said. "We take the PET images and co-register them with anatomical maps produced with magnetic resonance imaging (MRI), and use statistical techniques to do comparisons voxel by voxel. That allows us to identify which areas are more or less activated under the conditions we are exploring without any prior bias about what regions should be showing effects."

After they see a statistically significant effect, they use the MRI maps to identify the locations of those particular voxels to see what brain regions they are in.

"This opens it up to seeing an effect in any region in the brain -- even parts where you would not expect or think to look -- which could be a key to new discoveries," he said.

This work was supported by the intramural program at NIAAA as well as grants AA11034, AA07574, AA07611. Additional co-authors include: Lisa Robison and Ronald Kim, Stony Brook University; Eric J. Nestler and Michael Michaelides, Mount Sinai School of Medicine; Mary-Kay Lobo, University of Maryland School of Medicine; and Nora D. Volkow, NIAAA.


Story Source:

The above story is based on materials provided by Brookhaven National Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. P. K. Thanos, L. Robison, E. J. Nestler, R. Kim, M. Michaelides, M.-K. Lobo, N. D. Volkow. Mapping Brain Metabolic Connectivity in Awake Rats with PET and Optogenetic Stimulation. Journal of Neuroscience, 2013; 33 (15): 6343 DOI: 10.1523/JNEUROSCI.4997-12.2013

Cite This Page:

Brookhaven National Laboratory. "Lights, chemistry, action: New method for mapping brain activity." ScienceDaily. ScienceDaily, 10 April 2013. <www.sciencedaily.com/releases/2013/04/130410191602.htm>.
Brookhaven National Laboratory. (2013, April 10). Lights, chemistry, action: New method for mapping brain activity. ScienceDaily. Retrieved July 28, 2014 from www.sciencedaily.com/releases/2013/04/130410191602.htm
Brookhaven National Laboratory. "Lights, chemistry, action: New method for mapping brain activity." ScienceDaily. www.sciencedaily.com/releases/2013/04/130410191602.htm (accessed July 28, 2014).

Share This




More Mind & Brain News

Monday, July 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Losing Sleep Leaves You Vulnerable To 'False Memories'

Losing Sleep Leaves You Vulnerable To 'False Memories'

Newsy (July 27, 2014) A new study shows sleep deprivation can make it harder for people to remember specific details of an event. Video provided by Newsy
Powered by NewsLook.com
University Quiz Implies Atheists Are Smarter Than Christians

University Quiz Implies Atheists Are Smarter Than Christians

Newsy (July 25, 2014) An online quiz from a required course at Ohio State is making waves for suggesting atheists are inherently smarter than Christians. Video provided by Newsy
Powered by NewsLook.com
Beatings and Addiction: Pakistan Drug 'clinic' Tortures Patients

Beatings and Addiction: Pakistan Drug 'clinic' Tortures Patients

AFP (July 24, 2014) A so-called drugs rehab 'clinic' is closed down in Pakistan after police find scores of ‘patients’ chained up alleging serial abuse. Duration 03:05 Video provided by AFP
Powered by NewsLook.com
New Painkiller Designed To Discourage Abuse: Will It Work?

New Painkiller Designed To Discourage Abuse: Will It Work?

Newsy (July 24, 2014) The FDA approved Targiniq ER on Wednesday, a painkiller designed to keep users from abusing it. Like any new medication, however, it has doubters. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins