Finally, Zalc and colleagues developed a method of medium-throughput screening based on a transgenic tadpole model. Adding metronidazole to the water bath in which the tadpole swims causes a drastic reduction in the number of oligodendrocytes within the tadpole’s optic nerve. When researchers remove the metronidazole from the bath, new oligodendrocytes form within the optic nerve. Zalc and colleagues have used the model to analyze drugs that appear to promote remyelination, such as clemastine, benztropine, and retinoic acid.
One question that researchers have not resolved yet is whether newly formed myelin, which is thinner than normal myelin, is as durable as myelin formed in the normal way. “Twenty years after remyelination, will this myelin be as resistant as the normally made myelin? We don’t know. But at least for the short term or the medium term, this newly formed myelin seems to be as efficient as the usually formed myelin,” concluded Dr. Lubetzki.
—Erik Greb