Dharmendra S. Modha

This week’s Economist carried a story on the wiring diagram of the brain.  It is worth reading.

"The result of all this effort, it is hoped, will be precise circuit-diagrams of brains. The first brains to be mapped will probably have belonged to mice. Besides being cheap and disposable, a mouse brain weighs half a gram and packs a mere 16m neurons. Human brains (1.4kg and 100 billion neurons) will come later, when all the wrinkles have been ironed out in rodents, and proper methods devised to analyse the results. But come they will. And when they do, the most complicated object in the known universe will begin to give up the secrets of how it really works."

A very interesting proposal was published in PLoS computational Biology.

Abstract:

In this era of complete genomes, our knowledge of neuroanatomical circuitry remains surprisingly sparse. Such knowledge is critical, however, for both basic and clinical research into brain function. Here we advocate for a concerted effort to fill this gap, through systematic, experimental mapping of neural circuits at a mesoscopic scale of resolution suitable for comprehensive, brainwide coverage, using injections of tracers or viral vectors. We detail the scientific and medical rationale and briefly review existing knowledge and experimental techniques. We define a set of desiderata, including brainwide coverage; validated and extensible experimental techniques suitable for standardization and automation; centralized, open-access data repository; compatibility with existing resources; and tractability with current informatics technology. We discuss a hypothetical but tractable plan for mouse, additional efforts for the macaque, and technique development for human. We estimate that the mouse connectivity project could be completed within five years with a comparatively modest budget.