Upon superpositioning of existing target crystal structures with a neurotrophin-liganded ectodomain D5 complex of TrkB, it was deduced that the (binding) hotspot for the hitherto unknown tetanus/TrkB association could constitute the place (spot) on the (clostridial) Hc-TeNT fragment which corresponds to the ectodomain D5 of TrkB (Figure 7). Here, BDNF is linked to tetanus.