Control of Axon Selection

The term polarity is used to define asymmetry. In cell biology, it refers to describe the shape of a cell, the distribution of organelles, molecules and thus the intracellular trafficking of cellular components. How this asymmetry is attained in neurons is a question that has been under scrutiny as the shape of a neuron provides valuable clues to its function: Mature neurons extend dendrites and an axon to receive, process and propagate signals. A long-standing question in neurobiology is how neurons decide where the axon would form. One possibility is that external cues determine the position of axon extension. However, it is also possible that the intracellular organisation of the neuron determines where the axon will grow. Existing data provide evidence for both mechanisms playing a role during the axon selection, either concomitantly and/or sequentially.