Lysophosphatidyl choline facilitates labeling of CNS projections with horseradish peroxidase.

Previously, it has been difficult to label sensory terminations in the CNS by back-filling peripheral sensory nerves with horseradish peroxidase (HRP), apparently because the amount of HRP transported along the axons is insufficient. Labeling of central sensory projections in axolotls and frogs can be improved by agents known to disrupt membranes. Of those tested, L-alpha-lysophosphatidyl choline is the most effective. The addition of this detergent ot the HRP solution dramatically increases both the number of axons labeled and the density of label within single axons.