Organelle mapping in dendrites of human iPSC-derived neurons reveals dynamic functional dendritic Golgi structures

Secretory pathways within dendrites of neurons have been proposed for local transport of newly synthesized proteins. However, little is known about the dynamics of the local secretory system and whether the organelles are transient or stable structures. Here, we quantify the spatial and dynamic behavior of dendritic Golgi and endosomes during differentiation of human neurons generated from induced pluripotent stem cells (iPSCs). In early neuronal development, before and during migration, the entire Golgi apparatus transiently translocates from the soma into dendrites. In mature neurons, dynamic Golgi elements, containing cis and trans cisternae, are transported from the soma along dendrites, in an actin-dependent process. Dendritic Golgi outposts are dynamic and display bidirectional movement. Similar structures were observed in cerebral organoids. Using the retention using selective hooks (RUSH) system, Golgi resident proteins are transported efficiently into Golgi outposts from the endoplasmic reticulum. This study reveals dynamic, functional Golgi structures in dendrites and a spatial map for investigating dendrite trafficking in human neurons. [Display omitted] •Human neurons from iPSCs are polarized, functionally active, and fire spontaneously•Live imaging reveals distinct dynamics of the Golgi and endosomes within dendrites•Functional, mobile, dendritic Golgi mini-stacks are derived from the somatic Golgi•Actin, myosin II, and ROCK are required for the formation of Golgi outposts Wang et al. map the intracellular organelles of human iPSC-derived neurons and quantify the spatial and dynamic behavior of the Golgi and endosomes during neuronal differentiation. They demonstrate the existence of highly dynamic Golgi outposts in the dendrites of human neurons, which are dependent on actin and actin signaling.