KAIST 생명과학과동창회
  • News & Events
  • News


Astrocytes eat connections to maintain plasticity in adult brains


by The Korea Advanced Institute of Science and Technology (KAIST) 



    Astrocytes eat connections to maintain plasticity in adult brains

A 3-D image showing our synapse phagocytosis reporter in mouse hippocampus


Developing brains constantly sprout new neuronal connections called synapses as they learn and remember. Important connectionsthe ones that are repeatedly introduced, such as how to avoid dangerare nurtured and reinforced, while connections deemed unnecessary are pruned away. Adult brains undergo similar pruning, but it was unclear how or why synapses in the adult brain get eliminated.                      


Now, a team of KAIST researchers has found the mechanism underlying plasticity and, potentially, neurological disorders in adult brains. They published their findings on December 23 in Nature.


"Our findings have profound implications for our understanding of how neural circuits change during learning and memory, as well as in diseases," said paper author Won-Suk Chung, an assistant professor in the Department of Biological Sciences at KAIST. "Changes in synapse number have strong association with the prevalence of various neurological disorders, such as autism spectrum disorder, schizophrenia, frontotemporal dementia, and several forms of seizures."


Gray matter in the brain contains microglia and astrocytes, two complementary cells that, among other things, support neurons and synapses. Microglial are a frontline immunity defense, responsible for eating pathogens and dead cells, and astrocytes are star-shaped cells that help structure the brain and maintain homeostasis by helping to control signaling between neurons. According to Professor Chung, it is generally thought that microglial eat synapses as part of its clean-up effort in a process known as phagocytosis.


"Using novel tools, we show that, for the first time, it is astrocytes and not microglia that constantly eliminate excessive and unnecessary adult excitatory synaptic connections in response to neuronal activity," Professor Chung said. "Our paper challenges the general consensus in this field that microglia are the primary synapse phagocytes that control synapse numbers in the brain."


Professor Chung and his team developed a molecular sensor to detect synapse elimination by glial cells and quantified how often and by which type of cell synapses were eliminated. They also deployed it in a mouse model without MEGF10, the gene that allows astrocytes to eliminate synapses. Adult animals with this defective astrocytic phagocytosis had unusually increased excitatory synapse numbers in the hippocampus. Through a collaboration with Dr. Hyungju Park at KBRI, they showed that these increased excitatory synapses are functionally impaired, which cause defective learning and memory formation in MEGF10 deleted animals.


"Through this process, we show that, at least in the adult hippocampal CA1 region, astrocytes are the major player in eliminating synapses, and this astrocytic function is essential for controlling synapse number and plasticity," Chung said.


Professor Chung noted that researchers are only beginning to understand how synapse elimination affects maturation and homeostasis in the brain. In his group's preliminary data in other brain regions, it appears that each region has different rates of synaptic elimination by astrocytes. They suspect a variety of internal and external factors are influencing how astrocytes modulate each regional circuit, and plan to elucidate these variables.


"Our long-term goal is understanding how astrocyte-mediated synapse turnover affects the initiation and progression of various neurological disorders," Professor Chung said. "It is intriguing to postulate that modulating astrocytic phagocytosis to restore synaptic connectivity may be a novel strategy in treating various brain disorders."








List of Articles
번호 제목 글쓴이 날짜 조회 수
334 홍철암 박사과정(김학성 교수 Lab), ICMAT 2011에서 The Best Poster Award 수상! 과사무실 2011.07.06 14320
333 홍성태 박사, 하국선 박사, 2011년도 이공분야 "학문후속양성사업" 선정! 과사무실 2011.09.16 14564
332 허원도,김대수,한용만 교수 공동연구팀,Nature Biotechnology지에 표지논문 게재 file 생명과학과 2015.10.12 40279
331 허원도 교수와 양희원, 최하나 학생 Freshman Design Course에서 최우수상 수상! 과사무실 2009.09.07 14169
330 허원도 교수님_빛으로 RNA 이동과 단백질 합성 조절한다 file 생명과학과 2020.02.20 3495
329 허원도 교수님_머리에 빛을 비춰 신경세포 재생과 공간기억 향상 file 생명과학과 2020.04.27 2668
328 허원도 교수님_머리에 빛 비춰 공간기억 및 공감능력 높이는 광유전학 기술개발 file 생명과학과 2020.01.21 3996
327 허원도 교수님(유다슬이 박사)_제10회 에쓰-오일 우수학위논문상'의 생명과학 분야 대상 수상 생명과학과 2021.02.22 344
326 허원도 교수, 항체를 빛으로 활성화 시키는 항체광유전학 기술 개발 file 생명과학과 2019.10.28 4097
325 허원도 교수, 심장질환 원인신호 전달 메커니즘 규명 과사무실 2010.12.20 14895
324 허원도 교수, 빛만 비춰도 유전자 발현 조절하는 효소 개발 file 생명과학과 2019.01.21 5143
323 허원도 교수, 변화무쌍 스위치 단백질 관찰하는 바이오센서 개발 file 생명과학과 2019.01.16 5979
322 허원도 교수, 박혜림 박사, 김나연 박사과정 학생 Nature Communications지 논문 게재(2017.06) file 생명과학과 2017.06.26 15470
321 허원도 교수, 김진만 박사, 이민지 박사과정 학생 PNAS지에 논문 게재(2016.05) / Prof. Won-Do Heo, PhD. Jin-Man Kim and Min-Ji lee publish an article in PNAS (2016.05) 생명과학과 2016.05.18 12031
320 허원도 교수, 광유전학 신경세포 수용체 활성조절로 신경세포분화 운명 제어 성공(Cell Chemical Biology 표지논문 발표) file 생명과학과 2019.12.24 4109
319 허원도 교수, Trang T. T. Nguyen박사 PNAS지에 논문 게재(2016.08) / Prof. Won Do Heo, PhD. Trang T. T. Nguyen publish an article in PNAS (2016.08) 생명과학과 2016.08.25 13291
318 허원도 교수, Nature Methods지 11월호 This Month로 소개됨 file 생명과학과 2019.10.28 6852
317 허원도 교수, Nature Methods 게재 (2014. 5) 과사무실 2014.05.08 19849
316 허원도 교수, Nature Communications지 논문 게재 (2014. 6) 과사무실 2014.06.05 13268
315 허원도 교수, Nature Communications 게재(2013.2) 과사무실 2013.02.22 14474
Board Pagination Prev 1 2 3 4 5 6 7 8 9 10 ... 17 Next
/ 17