Nav: Home

Immune cells sculpt circuits in the brain

September 14, 2020

Immune cells play an unexpected role in fine-tuning the brain's neural circuits, according to research published in September, 2020 in Neuron. The immune cells that reside there, known as microglia, not only protect the brain from infection and inflammation, they also help physically sculpt circuits in the developing brain. The new work demonstrates that microglia also direct neurons to modify their own connectivity in response to sensory cues.

Cold Spring Harbor Laboratory (CSHL) Assistant Professor Lucas Cheadle discovered this cellular communication as a postdoctoral researcher in the laboratory of Michael Greenberg, a neuroscientist at Harvard Medical School. Cheadle's research explores the connections between biology and the external world, and he is particularly interested in how neural circuits are refined in response to sensory experience.

"To a large extent, the general architecture and wiring of the brain is accomplished by birth," he says. "But it really requires this robust feedback from the environment to continue that maturation." As an animal interacts with its surroundings, some neuronal connections are eliminated while others are strengthened, he explains. It's a process that, in humans, continues for decades after birth. Cheadle says:

"What's really important's that during development, the right neurons connect with one another in the right way. We want to have tight control over how many connections there are and how strong the connections are. So that's actually something that sensory experience is important for."

Cheadle and colleagues monitored the connections between neurons, or synapses, in a visual processing circuit in the brains of mice. Young mice need visual input at the right time to develop brain pathways related to vision. But if the mice lack visual input for a critical period, the circuits sprout too many synapses and the mice end up with abnormal connections. The team found that the circuits relied on microglia, which, with the right visual stimuli, signaled nearby neurons to prune some of the synapses.

This impact on neural connectivity represents a new role for microglia in the healthy brain, and could help explain why the cells have been implicated in autism and other neurodevelopmental disorders. "I think this study will be seen as a big breakthrough in our mechanistic understanding of how sensory experience and microglia coordinate the process of synaptic pruning that is critical for brain maturation in early life," Greenberg says.

At CSHL, Cheadle will investigate this interaction in more depth, tracing the molecular signals that lead to synapse disassembly as well as the changes that take place within microglia in response to environmental cues. "The very idea that microglia are able to upregulate the expression of genes in response to visual experience in and of itself is fascinating for me, because these are immune cells," he says.
-end-


Cold Spring Harbor Laboratory

Related Science Articles:

75 science societies urge the education department to base Title IX sexual harassment regulations on evidence and science
The American Educational Research Association (AERA) and the American Association for the Advancement of Science (AAAS) today led 75 scientific societies in submitting comments on the US Department of Education's proposed changes to Title IX regulations.
Science/Science Careers' survey ranks top biotech, biopharma, and pharma employers
The Science and Science Careers' 2018 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.
Science in the palm of your hand: How citizen science transforms passive learners
Citizen science projects can engage even children who previously were not interested in science.
Applied science may yield more translational research publications than basic science
While translational research can happen at any stage of the research process, a recent investigation of behavioral and social science research awards granted by the NIH between 2008 and 2014 revealed that applied science yielded a higher volume of translational research publications than basic science, according to a study published May 9, 2018 in the open-access journal PLOS ONE by Xueying Han from the Science and Technology Policy Institute, USA, and colleagues.
Prominent academics, including Salk's Thomas Albright, call for more science in forensic science
Six scientists who recently served on the National Commission on Forensic Science are calling on the scientific community at large to advocate for increased research and financial support of forensic science as well as the introduction of empirical testing requirements to ensure the validity of outcomes.
World Science Forum 2017 Jordan issues Science for Peace Declaration
On behalf of the coordinating organizations responsible for delivering the World Science Forum Jordan, the concluding Science for Peace Declaration issued at the Dead Sea represents a global call for action to science and society to build a future that promises greater equality, security and opportunity for all, and in which science plays an increasingly prominent role as an enabler of fair and sustainable development.
PETA science group promotes animal-free science at society of toxicology conference
The PETA International Science Consortium Ltd. is presenting two posters on animal-free methods for testing inhalation toxicity at the 56th annual Society of Toxicology (SOT) meeting March 12 to 16, 2017, in Baltimore, Maryland.
Citizen Science in the Digital Age: Rhetoric, Science and Public Engagement
James Wynn's timely investigation highlights scientific studies grounded in publicly gathered data and probes the rhetoric these studies employ.
Science/Science Careers' survey ranks top biotech, pharma, and biopharma employers
The Science and Science Careers' 2016 annual Top Employers Survey polled employees in the biotechnology, biopharmaceutical, pharmaceutical, and related industries to determine the 20 best employers in these industries as well as their driving characteristics.
Three natural science professors win TJ Park Science Fellowship
Professor Jung-Min Kee (Department of Chemistry, UNIST), Professor Kyudong Choi (Department of Mathematical Sciences, UNIST), and Professor Kwanpyo Kim (Department of Physics, UNIST) are the recipients of the Cheong-Am (TJ Park) Science Fellowship of the year 2016.
More Science News and Science Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.