Shining a light on growth cones

Neuronal growth cones have detergent-resistant membranes (DRMs), specialized cell membrane fractions enriched in GPI-anchored proteins and intracellular signaling molecules. But are the DRMs involved in regulating neurite outgrowth? Yes, say Nakai and Kamiguchi (page 1097), who developed a new technique for selectively disrupting DRMs, and used it to demonstrate the functional importance of these structures in neuronal growth cones for the first time.

The authors modified a technique called micro-scale chromophore-assisted laser inactivation (micro-CALI) to specifically disrupt the integrity of DRMs in living cells. A ligand with attached dye was bound to GM1 ganglioside in the DRMs. Upon laser irradiation, the dye produced short-lived free radicals that disrupted nearby membrane structures.

Disrupting DRMs in the peripheral domain stops growth cone migration on L1 or N-cadherin substrates, but not on a laminin substrate....