Brain cells are in constant motion. Ions rush in and out of synapses, the nubs that transmit messages between neurons, and trigger hundreds of protein interactions. Somehow, this chain of signals travels down neuronal branches to the cell body, where it can affect the expression of thousands of genes.To study these complex networks, scientists typically zero in on one gene — or even a part of a gene — at a time, then gradually work backwards to figure out what turned it on, when and why.That targeted approach seems ridiculously tedious compared with a new method that gives scientists the ability to simultaneously measure expression of the entire genome. A study applying the technique in brain cells is described today in Nature.Read more at...SFARI, April 2010.