Researchers from the laboratory of Darren Williams at the Centre for Developmental Neurobiology at King's College London have shown that axonal branch growth is regulated by dynamic, focal localisations of Neurexin and Neuroligin. The findings are published in the journal eLife.
Neurons are the most structurally diverse and complex cell type we know of and their tree-like arborisations are critical for collecting, integrating and disseminating information between different partners. During development, arborisations grow dynamically and this morphogenesis sets limits on their final location and the neurons they make connections with. We still have much to learn about the molecules and mechanisms responsible for creating these patterns of branching and connectivity.
William Constance, lead author of the study, said: “It has been exciting to develop a completely novel system to image complex arbor growth and then to use it to uncover a new and unexpected role for molecules that we are very familiar and known to be associated with autism.”
Darren and his colleagues demonstrated branch growth is driven by dynamic complexes formed between synaptic partners that they called ‘neuritic adhesion complexes’ (NACs). These complexes have a critical function in axonal arborization growth, prior to synapse formation. They specifically show that two proteins, Neurexin and Neuroligin play an active role in axonal branch growth.
This work was supported a Biotechnology and Biological Sciences Research Council grant (BB/L022672/1)
Paper reference: Constance WD, Mukherjee A, Fisher YE, Pop S, Blanc E, Toyama Y, Williams DW. Neurexin and Neuroligin-based adhesion complexes drive axonal arborisation growth independent of synaptic activity. Elife