Featured Post from Carnegie Mellon University

After 30 Years Neuroscientists Gain New Understanding of Neural Pathway

May 23, 2023

3 min

By: Caroline Sheedy


In a paper published in Neuron, Aryn Gittis and colleagues present new information about a neural pathway in the basal ganglia, a part of the brain important for skill learning, habit formation and motor control. The paper contradicts the model that has guided researchers’ understanding of motor learning for 30 years.


Gittis and team now have a better understanding of a neural pathway in the basal ganglia, a part of the brain important for skill learning, habit formation and motor control.


Gittis said there are two common theories about what happens in the basal ganglia.


“One school of thought is that the basal ganglia is for motor control — how you stop and go, the gas and brake pedals of the brain,” she explained. “Others think it is involved in learning and shaping movement. If a behavior leads to a reward, we do it more. If it prevents a reward, we stop doing that.”


In previous work, researchers showed that activating a specific pathway in the basal ganglia seemed to stop movement in animals, supporting the first theory. To understand why, Gittis and her team took a close look at what happens when specific cells in that pathway, called the ‘indirect pathway,” are activated.


“We show that when you activate those neurons, you're actually activating several pathways simultaneously,” Gittis said.


Gittis and her team found that this simultaneous activation of multiple pathways had caused previous researchers to draw the wrong conclusions about the function of the indirect pathway. Stimulating neurons at the beginning of the indirect pathway, D2 neurons, activate two other groups of cells, the globus pallidus (the next cell group in the indirect pathway) and D1 neurons which are part of a different neural pathway. It turned out that the motor effects produced by D2 stimulation that had been attributed to the indirect pathway were actually due to the spurious co-activation of D1 neurons which control motor function.


When experimental conditions were controlled to only activate the indirect pathway, Gittis and colleagues found that this pathway drives learning.


"Rather than driving motor control or directly affecting motor control, it’s shaping behavioral selection," Gittis said.


Since the pathway affects learning and behavior, it could serve as a target for compulsive behavior treatments in the future. When the indirect pathway is activated, it makes a behavior that was going to happen significantly less likely to happen in the short term. If the same pathway were activated in a person with a compulsive behavior, it could make them less likely to perform the specific compulsive behavior while not blocking all motor function.


Gittis said that this discovery could open doors to additional research, and is proud that her team was able to question long-standing theories.


"You need to question assumptions and really go directly to the data that has led to that assumption. Oftentimes there are gaps that actually hold the key to the discovery," she said.


Interested in learning more about a neural pathway in the basal ganglia? Then let us help with your coverage and questions. Aryn Gittis is available to speak with anyone looking to know more about this important discovery - simply click on her icon now to arrange an interview today!

You might also like...

Check out some other posts from Carnegie Mellon University

2 min

Is the economy on thin ice? Our expert can explain

Is the bubble about to burst again on the country's economy? A recent article by Bloomberg News paints a picture of what lies ahead - and the predictions look bleak at best. The Congressional Budget Office warned in its latest projections that US federal government debt is on a path from 97% of GDP last year to 116% by 2034 — higher even than in World War II. The actual outlook is likely worse. From tax revenue to defense spending and interest rates, the CBO forecasts released earlier this year are underpinned by rosy assumptions. Plug in the market’s current view on interest rates, and the debt-to-GDP ratio rises to 123% in 2034. Then assume — as most in Washington do — that ex-President Donald Trump’s tax cuts mainly stay in place, and the burden gets even higher.   With uncertainty about so many of the variables, Bloomberg Economics has run a million simulations to assess the fragility of the debt outlook. In 88% of the simulations, the results show the debt-to-GDP ratio is on an unsustainable path — defined as an increase over the next decade.  April 01 - Bloomberg The economy is in the news every day - and if you're a journalist looking to know what the future may hold - then let us help with your coverage and questions. Professor Lee Branstetter is a research associate of the National Bureau of Economic Research and nonresident senior fellow at the Peterson Institute for International Economics.   He is available to speak with media about the economy - simply click on his icon now to arrange an interview today.

2 min

#Experts in the Media: CMU's Rayid Ghani Weighs in on the Role of AI

The topic of Artificial Intelligence (AI) is beginning to dominate a lot of conversations and even conferences across the planet. And recently, Rayid Ghani, a Distinguished Career Professor in the Machine Learning Department and the Heinz College of Information Systems and Public Policy at Carnegie Mellon University was part of an in-depth article that explored if AI could be expected to play a positive role in the future of humankind.  In fact, it asked if we could soon expect AI to do the heavy lifting with regards to major problems like global warming that we're all trying to solve. The answers experts offered were varied and some a bit surprising but for the most part AI can help ... but we humans need to do a lot of the work. Today, AI is already proving itself in prediction and warning systems in the event of tornadoes or forest fires, for example. It is then necessary to evacuate populations, or for humans to agree to be vaccinated in the event of a pandemic, underlines Rayid Ghani, of Carnegie Mellon University. “We created this problem, not AI. Technology can help us… A little,” he clarified. “And only if humans decide to use it to tackle problems.” March 17 - The Archide  It is a fascinating article and well worth the read. And if you are a journalist looking to know more about Artificial Intelligence and what we can expect in the future - let us help with your coverage. Rayid Ghani is a reformed computer scientist who wants to increase the use of large-scale Machine Learning in solving large public policy. Rayid Ghani  is available to speak with media - simply click on his icon now to arrange an interview today.

3 min

CMU To Send Group of Satellites Into Orbit To Test Low-Cost Autonomous Swarming

Satellites designed by Carnegie Mellon University researchers to orbit in a swarm and maintain communication with each other while zipping around the Earth will test the latest in low-cost, CubeSat technology. The CMU team is monitoring four small satellites as they communicate with each other, determining where they are relative to one another and autonomously maneuvering to stay within communication range. The satellites have no propulsion systems but can change their orbital positions by adjusting their orientation in flight to increase or decrease drag. These maneuvers will allow the satellites to stay within a few hundred miles of each other and orbit in a loose formation relative to members of the swarm. “We’re trying to do really complicated, multiagent autonomy in a very small box,” said Zac Manchester, an assistant professor in the Robotics Institute at CMU’s School of Computer Science. “Our goal is to have these satellites act autonomously in a coordinated way. We want them to talk to each other, find out where their buddies are and stay close enough to maintain communication.” The goal of PY4 is to demonstrate low size, weight, power, and cost (SWaP-C) spacecraft-to-spacecraft ranging, in-orbit relative navigation, and coordinated simultaneous multi-point radiation measurements. Manchester’s Robotic Exploration Lab leads the project, known as PY4. The experiment is funded through a NASA Small Spacecraft Technology program grant, led by the agency’s Space Technology Mission Directorate, and managed by NASA’s Ames Research Center in Silicon Valley. The four CubeSats, each measuring 4 inches by 4 inches by 6.5 inches — about the size of a cracker box — launched Monday, March 4, aboard a SpaceX Falcon 9 rocket from Vandenberg Space Force Base in California. Max Holliday, middle, installs one of the four PyCubed-Based CubeSat (PY4) spacecraft into the Small Satellites Dispenser. The PY4 mission intends to demonstrate a low-cost approach to multiple-satellite missions. Advancing autonomy and proving that relatively small and inexpensive satellites can succeed could reduce mission and operational costs dramatically for subsequent missions. This technology demonstration aims to show that a group of low-cost small satellites provide the same functionality as larger, more costly spacecraft. Multiple satellites are needed for multipoint science data collection and for applications like positioning and tracking, stereo and 3D imaging of the Earth, and taking measurements to study the atmosphere and weather. Lowering the cost of these missions seeks to broaden the applications of multisatellite technology. “The big one that has been motivating us in the lab has been global wildlife tracking,” Manchester said. “We could have a number of low-cost satellites monitoring animals across the world to better understand the global impacts of poaching, illegal fishing, deforestation and climate change.” The satellites operate in low-Earth orbit at an altitude of about 342 miles (550 kilometers), slightly higher than the International Space Station. Solar panels snapped open once the satellites were in orbit to charge the batteries. The satellites orbit the Earth, passing over the poles at about 15,660 miles per hour (7 kilometers per second). The CMU team is monitoring the satellites but can only communicate directly with them using their own ground station during a five-minute window a few times per day. For the rest of the time, they rely on the Iridium constellation for communication with the satellites. A rendering of the satellites in orbit. In orbit, the satellites act autonomously. They periodically measure their relative distance to establish their positions in relation to each other. Combining this information with other sensor data available from the satellites allows them to control the configuration of the swarm. A maneuver such as changing the configuration of the swarm from a line to a box could take weeks. Manchester expects his team to gather all the data needed for their research in a few months. Zachary Manchester is a researcher and aerospace engineer with broad interests in dynamics, control, estimation and optimization.  If you're looking to know more about this project - simply click on his icon now to arrange an interview today.

View all posts
Powered by