Serotonin analog selectively ablates indentified neurons in the leech embryo.

Exposure of embryonic leeches to 5,7-dihydroxytryptamine a cytotoxic analog of the monoamine neurotransmitter serotonin, results in the selective ablation of serotonin-containing neurons in the ventral nerve cord. Other neurons appear to be unaffected by this treatment, including those that contain another monoamine neurotransmitter, dopamine. Embryos with ablations continue to develop into juvenile leeches, but as juveniles they are unable to make normal swimming movements. However, normal swimming movements can be instated in such leeches by injecting them with serotonin.