Get the picture? New high-res images show brain activity like never before

October 4, 2013 by Angela Herring
The human brain consists of [dozens] of anatomically unique areas, implicated in a variety of psychological functions. To tease out their unique activity patterns, researchers require high-resolution techniques only recently available. Credit: Thinkstock

(Medical Xpress)—In the middle of the human brain there is a tiny structure shaped like an elongated donut that plays a crucial role in managing how the body functions. Measuring just 10 millimeters in length and six millimeters in diameter, the hollow structure is involved in a complex array of behavioral, cognitive, and affective phenomena, such as the fight or flight response, pain regulation, and even sexual activity, according to Northeastern senior research scientist Ajay Satpute.

With a name longer than the structure itself, the "midbrain periaqueductal gray region," or PAG, is extraordinarily difficult to investigate in humans because of its size and intricate structure, he said.

In research published online this week in the journal Proceedings of the National Academy of Science, Satpute and his colleagues at Northeastern's Interdisciplinary Affective Science Laboratory explain how they hurdled these challenges by using state-of-the art imaging to capture this complex neural activity. The research could ultimately help scientists explore the grounds of human emotion like never before.

"The PAG's functional properties occur at such small spatial scales that we need to capture its activity at very high resolution in order to understand it," he explained.

Until recently, neuroimaging studies have been carried out on , or fMRI, instruments containing magnets of up to three Teslas, a measure of magnetic field strength. These instruments provide critical data for understanding how the brain's different areas respond to different stimuli, but when those areas become sufficiently small and complicated, their resolution falls short.

Using a high-field strength fMRI magnet, Ajay Satpute and his colleagues in the Interdisciplinary Affective Science Laboratory achieved images of the human brain stem (left and center) at resolutions not possible before (right). Credit: Ajay Satpute

In the case of the tiny PAG, this problem is paramount because the PAG wraps around a hollow core, or "aqueduct," containing cerebrospinal fluid, Satpute said. Traditional fMRI instruments cannot distinguish occurring in the PAG from that occurring in the CS fluid. Even more difficult is identifying where within the PAG itself specific responses originate.

In collaboration with researchers at the Massachusetts General Hospital in Boston, Satpute and his colleagues used a high-tech fMRI instrument that contains a seven-Tesla magnet. The force of the instrument is so strong (albeit harmless) that one can feel its pull when simply walking by. Coupled with painstaking manual data analyses, Satpute was able to resolve activity in sub-regions of the PAG with more precision than ever before.

With their method in hand, the research team showed 11 human research subjects images of burn victims, gory injuries, and other content related to threat, harm, and loss while keeping tabs on the PAG's activity. Researchers also showed the subjects neutral images such and then compared results between the two scenarios.

The proof-of-concept study showed emotion-related activity concentrated in particular areas of the PAG. While similar results have been demonstrated in animal models, nothing like it had previously been shown in human brains.

Using this methodology, the researchers said they would not only gain a better understanding of the PAG but also be able to investigate a range of brain-related research questions beyond this particular structure.

Seven-Tesla brain imaging provides an unprecedented view of regions like the PAG while they respond to stimuli, said Lisa Feldman Barrett, director of the Interdisciplinary Affective Science Laboratory. "Studies like this are a critical step forward in bridging human and nonhuman animal studies of emotion, because they offer a level of resolution in that was previously possible only in studies of non-human animal," she said.

Explore further: A new tool for brain research

More information: … /1306095110.abstract

Related Stories

A new tool for brain research

July 31, 2013
Physicists and neuroscientists from The University of Nottingham and University of Birmingham have unlocked one of the mysteries of the human brain, thanks to new research using functional Magnetic Resonance Imaging (fMRI) ...

Recommended for you

Cognitive cross-training enhances learning, study finds

July 25, 2017
Just as athletes cross-train to improve physical skills, those wanting to enhance cognitive skills can benefit from multiple ways of exercising the brain, according to a comprehensive new study from University of Illinois ...

Brain disease seen in most football players in large report

July 25, 2017
Research on 202 former football players found evidence of a brain disease linked to repeated head blows in nearly all of them, from athletes in the National Football League, college and even high school.

Lutein may counter cognitive aging, study finds

July 25, 2017
Spinach and kale are favorites of those looking to stay physically fit, but they also could keep consumers cognitively fit, according to a new study from University of Illinois researchers.

Zebrafish study reveals clues to healing spinal cord injuries

July 25, 2017
Fresh insights into how zebrafish repair their nerve connections could hold clues to new therapies for people with spinal cord injuries.

Brain stimulation may improve cognitive performance in people with schizophrenia

July 24, 2017
Brain stimulation could be used to treat cognitive deficits frequently associated with schizophrenia, according to a new study from King's College London.

New map may lead to drug development for complex brain disorders, researcher says

July 24, 2017
Just as parents are not the root of all their children's problems, a single gene mutation can't be blamed for complex brain disorders like autism, according to a Keck School of Medicine of USC neuroscientist.


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.