Looking for Guidance - Models and Methods to Study Axonal Navigation

The molecular mechanisms of neural circuit formation have been of interest to Santiago Ramo acute accent n y Cajal and thousands of neuroscientists sharing his passion for neural circuits ever since. Cajal was a brilliant observer and taught us about the connections and the morphology of neurons in the adult and developing nervous system. Clearly, we will not learn about molecular mechanisms by just looking at brain sections or cells in culture. Tech-nically, we had to come a long way to today's possibilities that allow us to perturb target gene expression and watch the consequences of our manipulations on navigating axons in situ. In this review, we summarize landmark steps towards modern live-imaging approaches used to study the molecular basis of axon guidance.This article is part of a Special Issue entitled: Prof. Friedrich Bonhoeffer.(c) 2022 The Author(s). Published by Elsevier Ltd on behalf of IBRO. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).