Mark Bear Explained

Mark Bear
Awards:	National Academy of Medicine

Mark Firman Bear is an American neuroscientist. He is currently the Picower Professor of Neuroscience at The Picower Institute for Learning and Memory at Massachusetts Institute of Technology. He is a former Howard Hughes Medical Institute Investigator;^[1] an Elected Fellow of the American Association for the Advancement of Science and the American Academy of Arts and Sciences;^[2] and a Member of the National Academy of Medicine.^[3]

Education and career

Bear earned a B.Sc. degree from Duke University and received his doctorate in neurobiology at Brown University. As a postdoctoral fellow, he trained with Wolf Singer at the Max Planck Institute for Brain Research in Frankfurt, Germany, and with Leon Cooper at Brown.

Bear was the Sidney A. and Dorothy Doctors Fox Professor at Brown University's Alpert Medical School from 1996 to 2003, when he was appointed Picower Professor of Neuroscience at The Picower Institute for Learning and Memory in the Department of Brain and Cognitive Sciences at MIT. He subsequently served as Director of The Picower Institute from 2007 to 2009. Bear was an Investigator of the Howard Hughes Medical Institute from 1994 to 2015.

Scientific focus

Bear's research focuses on understanding developmental plasticity in the visual cortex and experience-dependent synaptic modification in visual cortex and hippocampus. He has described novel forms of procedural learning in the visual system, and investigated synaptic function in models of fragile X syndrome and other autism spectrum disorders.^{[4] [5]} His long-standing scientific interest is in how the brain is modified by experience, and his lab is currently focused on applying knowledge of the elementary mechanisms of synaptic plasticity to overcome genetic or environmental adversity.

Selected scientific discoveries

Bear's work has led to several significant contributions to science, which include:

• the concept of metaplasticity as a means to maintain network homeostasis ^{[6] [7]}
• the molecular basis for amblyopia, a prevalent form of visual impairment, showing that the synaptic weakening is actively triggered by the noisy residual activity in the eye deprived of vision ^{[8] [9]}
• the first direct demonstrations that learning induces long-term potentiation, or LTP, in the hippocampus and visual cortex^{[10] [11]}
• formulation of the mGluR theory of fragile X and its experimental validation ^{[12] [13]}

Selected publications

• Bear, Mark F., Barry W. Connors, and Michael A. Paradiso, eds. Neuroscience. Vol. 2. Lippincott Williams & Wilkins, 2007.
• Malenka, Robert C., and Mark F. Bear. "LTP and LTD: an embarrassment of riches." Neuron 44.1 (2004): 5-21.
• Bear, Mark F., Kimberly M. Huber, and Stephen T. Warren. "The mGluR theory of fragile X mental retardation." Trends in neurosciences 27.7 (2004): 370–377.
• Abraham, Wickliffe C., and Mark F. Bear. "Metaplasticity: the plasticity of synaptic plasticity." Trends in neurosciences 19.4 (1996): 126–130.
• Bear, Mark F., and Robert C. Malenka. "Synaptic plasticity: LTP and LTD." Current Opinion in Neurobiology 4.3 (1994): 389–399.
• Dudek, Serena M., and Mark F. Bear. "Homosynaptic long-term depression in area CA1 of hippocampus and effects of N-methyl-D-aspartate receptor blockade." Proceedings of the National Academy of Sciences 89.10 (1992): 4363–4367.
• Bear, Mark F., and Wolf Singer. "Modulation of visual cortical plasticity by acetylcholine and noradrenaline." (1986): 172–176.

Notes and References

1. Web site: Mark F. Bear. 2022-02-12. HHMI. en.
2. Web site: Mark Firman Bear. 2022-02-12. American Academy of Arts & Sciences. en.
3. Web site: Five with MIT ties elected to the National Academy of Medicine for 2022 . 2022-11-21 . MIT News Massachusetts Institute of Technology . 18 October 2022 . en.
4. Web site: Langreth . Robert . Mark Bear's Fight To Decode Autism . 2022-02-12 . Forbes . en.
5. Web site: Understanding Autism . 2022-02-12 . MIT Technology Review . en.
6. Abraham . W. C. . Bear . M. F. . Metaplasticity: the plasticity of synaptic plasticity . Trends in Neurosciences . 1996 . 19 . 4 . 126–130 . 10.1016/s0166-2236(96)80018-x . 8658594 . 206027600 .
7. Kirkwood . A. . Rioult . M. C. . Bear . M. F. . Experience-dependent modification of synaptic plasticity in visual cortex . Nature . 1996 . 381 . 6582 . 526–528 . 10.1038/381526a0 . 8632826 . 1996Natur.381..526K . 2705694 .
8. Rittenhouse . C. D. . Shouval . H. Z. . Paradiso . M. A. . Bear . M. F. . Monocular deprivation induces homosynaptic long-term depression in visual cortex . Nature . 1999 . 397 . 6717 . 347–350 . 10.1038/16922 . 9950426 . 1999Natur.397..347R . 4302032 .
9. Frenkel . Mikhail Y. . Bear . Mark F. . How monocular deprivation shifts ocular dominance in visual cortex of young mice . Neuron . 2004 . 44 . 6 . 917–923 . 10.1016/j.neuron.2004.12.003 . 15603735 . free .
10. Cooke . Sam F. . Bear . Mark F. . Visual Experience Induces Long-Term Potentiation in the Primary Visual Cortex . The Journal of Neuroscience . 1 December 2010 . 30 . 48 . 16304–16313 . 10.1523/JNEUROSCI.4333-10.2010 . 21123576 . 3078625 .
11. Kaplan . Eitan S. . Cooke . Sam F. . Komorowski . Robert W. . Chubykin . Alexander A. . Thomazeau . Aurore . Khibnik . Lena A. . Gavornik . Jeffrey P. . Bear . Mark F. . Contrasting roles for parvalbumin-expressing inhibitory neurons in two forms of adult visual cortical plasticity . eLife . 2016 . 5 . e11450 . 10.7554/eLife.11450 . 4786407 . 26943618 . free .
12. Bear . Mark F. . Huber . Kimberly M. . Warren . Stephen T. . The mGluR theory of fragile X mental retardation . Trends in Neurosciences . 2004 . 27 . 7 . 370–377 . 10.1016/j.tins.2004.04.009 . 15219735. 13421753 .
13. Auerbach . Benjamin D. . Osterweil . Emily K. . Bear . Mark F. . 2011-11-23 . Mutations causing syndromic autism define an axis of synaptic pathophysiology . Nature . en . 480 . 7375 . 63–68 . 10.1038/nature10658 . 22113615 . 3228874 . 2011Natur.480...63A .