Transcript connectome - LjcdsNeuro2011

Jerry Hsiung
What is a connectome
Complete description of the structural connectivity of an organism’s nervous
system
Goal
Open source data bank
Understanding brain connectivity
Participants
UCLA, Wash U, Harvard, U of Minnesota.
National Institutes of Health
Timeline of brain research
• 450BC The Greek physician Alcmaeon concludes that the brain is the central organ for sensation and not the heart as
previously believed by Pythagorian thinkers.
• 300BC The first detailed account of the structure of the brain is completed by the Alexandrian biologists Herophilus and
Erasistratus. They back Alcmaeon's theory that the brain is the centre of human intelligence.
• 1027 The oldest drawing of the nervous system is traced to Cairo. Ibn al-Haytham sketched a nose and two eyes and ran
hollow nerves from the latter to the brain.
• 1400s Leonardo da Vinci set out to discover the link between the senses and the soul by studying, and sketching, the
brain of a dead ox.
• 1873 Italian physician Camillo Golgi develops the reazione nera, the "black reaction". The simple mixture of potassium
dichromate and silver nitrate gave scientists the ability to stain, and highlight, individual brain cells.
• 1890s The Spaniard Santiago Rámon y Cajal adopts Golgi's method and proves the brain is a collection of individual but
interconnected neurons.
• 1929 The EEG, electroencephalogram, is created by the Swiss inventor Hans Berger. The technique is still used
diagnostically in neurology and psychiatry.
• 1970s Invention of magnetic resonance imaging (MRI), now used commonly for brain scans.
• 1970s Neuroscientists use an enzyme called horseradish peroxidase to trace neural tracts in animal brains.
• 1974 US scientists Edward J Hoffman and Michael E Phelps invent the positron emission tomography, whole -body
scanner.
• 1990 Functional MRI is invented by Seiji Ogawa at Bell Laboratories in the US. The images reveal changes in blood flow
in the brain over time.
• 2007 Jeff Lichtman at Harvard University adds fluorescence genes into growing neurons to produce spectacular
multicoloured "brainbows".
History
1986  worm C. elegans (300 neurons = 7000
connections)
Electron Microscope
New ways to scan the brain
Diffusion MRI
Diffusion Tensor Imaging
Diffusion Spectrum Imaging.
Technical Challenges
One Petabyte (1024 terabytes) of computer memory stores the image of
1mm cube of mouse rain.
Case study
before
UCLA  The famous railroad worker, Phineas Gage.
Connectome looks at his brain damage.
after
Videos
Ted Talk  http://www.ted.com/talks/sebastian_seung.html
Brain Science interview 
http://ec.libsyn.com/p/5/3/6/536a17214e66b8ed/BSP_85Seung.mp3?d13a76d516d9dec20c3d276ce028ed5089ab1ce3dae902ea1d01c
b8f35d2c05cd7c8&c_id=4560204
IdeaLab at MIT  http://www.youtube.com/watch?v=sH9zccNtNlA
Sources
http://www.scholarpedia.org/article/Connectome
Good image  http://neurosciencenews.com/brain-wiring-a-no-brainerdiffusion-spectrum-imaging/
http://www.guardian.co.uk/science/neurophilosophy/2012/may/16/neuroscie
nce-psychology#_