The atypical thought processes of people with autism suggest that the brain wiring in those with the disorder has gone awry, but this hypothesis has been difficult to test. Dr. Sanes and his colleagues aim to search for this aberrant wiring with new methods. A new resource known as the "brainbow" mouse may be able to reveal these complex connections. Using a simple genetic trick, each neuron in these mice is made to express a random assortment of fluorescent proteins to paint each cell a unique color. Beautiful and striking, the brains of these mice allow researchers to follow individual neurons through the brain with an ease not previously possible. Researchers intend to use the technique to follow the development of mice with mutations in autism-associated genes, looking for disparities between these mice and controls in the way neurons intertwine and connect and determining whether the mutations alter these patterns. They aim to determine the composition of synapses, looking for factors that might influence the activity or targeting of the neurons. Finally, they plan to measure the neurons' signaling activity at synapses, using a high-throughput method known as multi-electrode analysis. Knowing which neurons are abnormal and how they are different may hint at the developmental mechanisms altered in autism and even how to correct them.