Abe, et al. The Journal of Neuroscience, 2015.
The brain contains many different types of neurons that are wired together in circuits. These circuits form in development, and defects in their assembly are thought to underlie developmental disorders such as autism and schizophrenia.
In order to link up with other neurons in the circuit, some neurons have to send their axons — cable-like extensions that transmit neural signals — to distant parts of the brain. The image above shows one hemisphere of an embryonic mouse brain, with neurons in the thalamus (green triangular structure) sending axons to immature cells in the cerebral cortex (red). By studying how these axons find their way to the right cells, scientists hope to learn how neural circuits are assembled and why this process sometimes goes awry.