Neuronal receptive endings (for example, sensory protrusions) are remodelled by experience; but how do they acquire their new shape? To address this question, Shai Shaham and co-workers have been studying the remodelling of sensory neuron receptive endings that occurs in C. elegans during dauer (a developmental state induced by environmental stressors). They now report that glial cells delimit this remodelling in response to external cues (see p. ). Nematodes have two AWC (olfactory) neurons, each of which is enveloped by an amphid sheath (AMsh) glial cell. The researchers show that AMsh glial remodelling is required for the shape changes in AWC sensory neuron receptive endings in dauers, and that glial remodelling requires the AFF-1 fusogen, the transcription factor TTX-1 and probably the VEGFR-related protein VER-1. The expression of ver-1, they report, requires binding of TTX-1 to ver-1 regulatory sequences, and is induced by dauer entry. Together, these results suggest that stimulus-induced changes in glial compartment size spatially constrain the growth of neuronal receptive endings.
