During development, axons form branches in response to extracellular molecules. Little is known about the underlying molecular mechanisms. Here, we investigate how neurotrophin-induced axon branching is related to synaptic vesicle cycling for thalamocorti-cal axons.The exogenous application of brain-derived neurotrophic factor (BDNF) markedly increased axon branching in thalamocortical co-cultures, while removal of endogenous BDNF reduced branching. Over-expression of a C-terminal fragment of AP180 that inhibits clathrin-mediated endocytosis affected the laminar distribution and the number of branch points. A dominant-negative synaptotagmin mutant that selectively targets synaptic vesicle cycling, strongly suppressed axon branching. Moreover, axons expressing the mutant synaptotagmin were resistant to the branch-promoting effect of BDNF. These results suggest that synaptic vesicle cycling might regulate BDNF induced branching during the development of the axonal arbor. © 2013 Granseth, Fukushima, Sugo, Lagnado and Yamamoto.
Granseth, B., Fukushima, Y., Sugo, N., Lagnado, L., & Yamamoto, N. (2013). Regulation of thalamocortical axon branching by BDNF and synaptic vesicle cycling. Frontiers in Neural Circuits, 7(DEC). https://doi.org/10.3389/fncir.2013.00202