Understanding how functional neuronal circuits are established during development is a fundamental challenge in neuroscience. During development, the complex neuronal circuitry of the brain arises from limited information contained in the genome. After the genetic code instructs the birth of neurons, the emergence of brain regions, and the formation of axon tracts, it is believed that neural activity plays a critical role in shaping circuits for behavior. Current Artificial Intelligence technologies are modeled after the same principle: connections in an initial weight matrix are pruned and strengthened by activity-dependent signals until the network can sufficiently generalize a set of inputs into outputs. In Nature Communications, Gregor Schuhknecht, Florian Engert and I challenge these learning-dominated assumptions by showing that neuronal activity contributes minimally, if at all, to the development of a visually-guided swimming behavior in larval zebrafish.
