(ISNS) -- Hundreds of billions of neurons tangle together into the two pounds of folded, wrinkly tissue we call the brain. Scientists have spent years trying to eavesdrop on electrochemical signals -- neuronal chatter -- to figure out what happens when a memory is formed or an emotion is felt. Scientists have recently moved beyond implanting electrodes and using functional MRI scans to begin harnessing the power of cell culture and microchips