Assembling a Cellular User Manual for the Brain.

For many years, efforts to decipher the various cellular components that comprise the CNS were stymied by a lack of technical strategies for isolating and profiling the brain's resident cell types. The advent of transcriptional profiling, combined with powerful new purification schemes, changed this reality and transformed our understanding of the macroglial populations within the brain. Here, we chronicle the historical context and scientific setting for our efforts to transcriptionally profile neurons, astrocytes, and oligodendrocytes, and highlight some of the profound discoveries that were cultivated by these data.Following a lengthy battle with pancreatic cancer, Ben Barres passed away during the writing of this Progression piece. Among Ben's innumerable contributions to the greater scientific community, his addition of publicly available transcriptome databases of CNS cell types will forever remain a relic of his generous spirit and boundless scientific curiosity. Although he had impressively committed a majority of these enormous gene lists to memory, Ben could oftentimes be spotted at meetings buried in his cell phone on the Barres RNAseq database. Perhaps the only thing he enjoyed more than exploring these data himself, was knowing how useful these contributions had been (and will hopefully continue to be) to his scientific peers.