Henry Markram

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Henry Markram: Visualizing Synaptic Maps onto Neocortical Neurons
Henry Markram: Visualizing Synaptic Maps onto Neocortical Neurons

Henry Markram is Director of the Blue Brain Project, Director of the Center for Neuroscience & Technology and co-Director of the Brain Mind Institute at École Polytechnique Fédérale de Lausanne (EPFL).

He obtained his B.Sc. (Hons) from Cape Town University, South Africa under the supervision of Rodney Douglas and his Ph.D. from the Weizmann Institute of Science, Israel, under the supervision of Menahem Segal. During his Ph.D. work, he discovered a link between acetylcholine and memory mechanisms by showing that acetylcholine modulates the primary receptor linked to synaptic plasticity.

Markram went to the United States as a Fulbright Scholar at the National Institutes of Health (NIH), where he studied ion channels on synaptic vesicles. He then went as a Minerva Fellow to the Laboratory of Bert Sakmann at the Max Planck Institute, Heidelberg, Germany, where he discovered calcium transients in dendrites evoked by sub-threshold activity, and by single action potentials propagating back into dendrites. He also began studying the connectivity between neurons, describing in great detail how layer 5 pyramidal neurons are interconnected.

He was the first to alter the precise millisecond relative timing of single pre- and post-synaptic action potentials to reveal a highly precise learning mechanism operating between neurons - now reproduced in many brain regions and known as spike timing-dependent synaptic plasticity (STDP). These experiments were carried out in 1993, four years before publication. Although there were some correlation-sensitive findings before, this was the first study that manipulated single pre- and post-synaptic spike times to monitor the effect of synaptic changes.

Markram was appointed assistant professor at the Weizmann Institute of Science, where he started systematically dissecting out the neocortical column. He discovered that synaptic learning can also involve a change in synaptic dynamics (called redistribution of synaptic efficacy) rather than merely changing the strengths of connections. He also revealed a spectrum of new principles governing neocortical microcircuit structure, function, and emergent dynamics. Based on the emergent dynamics of the neocortical microcircuit he and Wolfgang Maass developed the theory of liquid computing, or high entropy computing.

In 2002 he moved to EPFL as full professor and founder/director of the Brain Mind Institute and Director of the Center for Neuroscience and Technology. At the BMI, in the Laboratory for Neural Microcircuitry, Markram has continued to unravel the blueprint of the neocortical column, building state-of-the-art tools to carry out multi-neuron patch clamp recordings combined with laser and electrical stimulation as well as multi-site electrical recording, chemical imaging and gene expression. Markram has received numerous awards and published over 75 papers.

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