The action of neurotrophins, factors that modulate the differentiation, maturation and neuronal regeneration, and even death of neurons, is carried out through specific receptors. Among them, the Trk A tyrosine kinase with activity. After activation, these receptors give rise to an intracellular signaling cascade, which culminates with the expression of certain genes.

So far, these receptors were found only in vertebrates, and the search had been barren of invertebrates, made in the two most widely used models, Drosophila melanogaster and Caenorhabditis elegans, as their appearance was related to the evolution of early vertebrates. However, a paper published in Development, in collaboration between the universities of Barcelona and Lleida, has identified the Trk