It was designated F1, then B-50, then GAP43, pp46, and finally neuromodulin, each name reflecting a different function of the same molecule. F1 was localized to synapses, and was increased in its phosphorylation one day after learning.
The molecule was initially designated F1, then B-50, followed by GAP43, pp46, and finally neuromodulin, each name highlighting a different role it plays.