Terrence J. Sejnowski
BS, Physics, Case Western Reserve University
PhD, Physics, Princeton University
Postdoctoral fellow, Biology, Princeton; Neurobiology, Harvard Medical School
Terrence J. Sejnowski, professor and head of the Computational Neurobiology Laboratory, is a pioneer in the field of computational neuroscience.
Among other things, Sejnowski is interested in the hippocampus, believed to play a major role in learning and memory; and the cerebral cortex, which holds our knowledge of the world and how to interact with it. In his lab, Sejnowski's team uses sophisticated electrical and chemical monitoring techniques to measure changes that occur in the connections among nerve cells in the hippocampus during a simple form of learning. They use the results of these studies to instruct large-scale computers to mimic how these nerve cells work. By studying how the resulting computer simulations can perform operations that resemble the activities of the hippocampus, Sejnowski hopes to gain new knowledge of how the human brain is capable of learning and storing memories. This knowledge ultimately may provide medical specialists with critical clues to combating Alzheimer's disease and other disorders that rob people of the critical ability to remember faces, names, places and events.
"My goal is to discover the principles linking brain mechanisms and behavior. My laboratory uses
both experimental and modeling techniques to study the biophysical properties of neurons and
synapses, the sites at which neurons connect with each other, as well as the population dynamics of
large networks of neurons."
Multiple sclerosis affects an estimated
400,000 Americans and more than 2.5
million people worldwide. A chronic, often
disabling disease that attacks the central
nervous system, it is characterized by a
baffling range of neurological symptoms,
including numbness, tingling, motor weakness,
paralysis and vision loss. It is thought
to result when the immune system attacks
the myelin sheath that insulates axons, the
nerve fibers that conduct electrical impulses
to and from the brain and between neurons
within the brain. Ordinarily, the myelin
speeds up the signals the axons transmit,
but when axons lose their insulation, either
signal conduction fails because the demyelinated
axons are unable to generate an
impulse, or the axons become hyperexcitable
and overcompensate by firing even in the
absence of an input.
The first computer model of axonal transmission,
developed in the 1950s for the giant
axon of the squid, which lacks myelin,
tracked positively charged sodium and potassium
ions, whose movements across the
neuronal membrane generate the necessary
electrical signals. Building on that model,
Sejnowski and his team included myelin in
their own model, then demyelinated one of
the sections and incorporated all the changes
known to take place as a result. Most prior
studies had focused on the sodium channel
because it is responsible for initiating the
electrical signal. But to everyone's surprise,
Sejnowski's group found that it was the ratio
of densities between the sodium channel and
a previously ignored but ubiquitous voltageinsensitive
potassium current, called the leak
current, that determines whether neurons
can fire properly.
If the sodium level drops, an accompanying
drop in the leak current will maintain the
signal, whereas if the sodium drops but
the leak current doesn't, signal transmission
may fail. Conversely, if the sodium level is
too high and the leak current doesn't increase,
a patient may experience twitching.
Sejnowski's model not only offers an explanation
for many of the bizarre symptoms that
multiple sclerosis patients experience but
could also provide a new target for drugs
that increase or decrease the potassium leak
current to maintain a constant ratio and
Awards and Honors
- Presidential Young Investigator Award, 1984-89
- Fairchild Distinguished Scholar, 1992-93
- Wright Prize, 1996
- Hebb Prize, 1999
- IEEE Fellow, 2000
- Neural Network Pioneer Award, 2002
- Johns Hopkins Society of Scholars, 2003
- Francis Crick Chair funded by the J.W. Kieckhefer Foundation, 2004
- American Association Advancement of Science Fellow, 2006
- National Research Council of National Academies, 2008
- National Academy of Medicine, 2008
- National Academy of Sciences, 2010
- National Academy of Engineering, 2011
Sejnowski, T. J. and Rosenberg, C. R., Parallel networks that learn to pronounce English text, Complex Systems 1, 145-168 (1987).
Steriade, M., McCormick, D. A., Sejnowski, T. J., Thalamocortical oscillations in the sleeping and aroused brain, Science 262, 679-685 (1993).
Bell, A. J. and Sejnowski, T. J., An information-maximization approach to blind separation and blind deconvolution, Neural Computation 7, 1129-1159 (1995).
Mainen, Z. F. and Sejnowski, T. J., Reliability of spike timing in neocortical neurons, Science 268, 1503-1506 (1995).
Laughlin, S. B., and Sejnowski, T. J., Communication in neuronal networks, Science 301, 1870-1874 (2003).
Coggan, J. S., Bartol, T. M., Esquenazi, E., Stiles, J. R., Lamont, S., Martone, M. E., Berg, D. K., Ellisman, M. H., and Sejnowski, T. J., Evidence for ectopic neurotransmission at a neuronal synapse, Science, 39, 446-451 (2005).
Tiesinga, P.; Sejnowski, T. J.; Cortical enlightenment: Are gamma oscillations driven by ING or PING? Neuron, 63: 727-732 (2009).
Meltzoff, A. N., Kuhl, P. K., Movellan, J., Sejnowski, T. J., Foundations for a new science of learning, Science 325: 284-288 (2009).
Wang, H.P., Spencer, D., Fellous, J.-M., Sejnowski, T. J., Synchrony of Thalamocortical Inputs Maximizes Cortical Reliability, Science, 328: 106-109 (2010).
Lister, R., Mukamel, E. A., Nery, J. R., Urich, M., Puddifoot, C. A., Johnson, N. D., Lucero, J., Huang, y., Dwork, A., Schultz, M. D., Tonti-Filippini, J., Yu, M.; Heyn, H.; Hu, S.; Wu, J. C.; Rao, A.; Esteller, M.; He, C.; Haghighi, F. G., Sejnowski, T. J., Behrens, M. M., Ecker, J. R., Global epigenomic reconfiguration during mammalian brain development, Science, 341, 629, (2013).
Salk News Releases
- Receptors in brain linked to schizophrenia, autism, August 11, 2015
- Memory relies on astrocytes, the brain's lesser-known cells, July 28, 2014
- Scientists explain how memories stick together, April 16, 2014
- Unique epigenomic code identified during human brain development, July 4, 2013
- Salk scientist Terrence Sejnowski elected to American Academy of Arts and Sciences, April 24, 2013
- Salk applauds Obama's ambitious BRAIN Initiative to research human mind, April 2, 2013
- Salk professor Terrence Sejnowski receives IEEE Frank Rosenblatt Award, July 26, 2012
- Salk professor Terrence Sejnowski elected to National Academy of Engineering, February 8, 2011
- Decoding the disease that perplexes: Salk scientists discover new target for MS, October 25, 2010
- Salk scientist Terrence Sejnowski elected to National Academy of Sciences, April 27, 2010
- All for one and one for all!, April 1, 2010
- New science of learning offers preview of tomorrow, July 17, 2009
- Salk Researcher Terry Sejnowski Elected to Institute of Medicine, October 14, 2008
- Salk scientists named 2006 AAAS Fellows, November 29, 2006
- Salk scientists overturn a dogma of nerve cell communication, July 14, 2005
- New Light on How the Brain Handles Brightness, June 23, 2004
- Salk Researcher Provides New View on How the Brain Functions, September 25, 2003
- New Book Reveals Complexities Of The Human Mind, November 18, 2002
- New View of Brain's Inner Workings Opens Research Into Autism, Other Disorders, January 24, 2002
- We Live In The Past, Salk Scientists Discover, March 16, 2000
- Computer Program Trained To Read Faces Developed By Salk Team, March 17, 1999
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