AUTHOR=Granseth Björn , Fukushima Yuichi , Sugo Noriyuki , Lagnado Leon , Yamamoto Nobuhiko TITLE=Regulation of thalamocortical axon branching by BDNF and synaptic vesicle cycling JOURNAL=Frontiers in Neural Circuits VOLUME=7 YEAR=2013 URL=https://www.frontiersin.org/journals/neural-circuits/articles/10.3389/fncir.2013.00202 DOI=10.3389/fncir.2013.00202 ISSN=1662-5110 ABSTRACT=

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 thalamocortical 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.