A map of the mouse brain down to details of individual cells has been completed, the first project of an institute funded by Microsoft Corp. co-founder Paul G. Allen, it was announced Tuesday. The new Allen Brain Atlas is being made available online without cost to neuroscientists studying brain circuits and chemistry, a potential boon to cancer and other disease research because of similarities between the brains of mice and human beings, according to a statement issued by the Allen Institute of Brain Science. "We want people to use this and make discoveries," Dr. Allan Jones, the institute's chief scientific...