Polarized secretory trafficking directs cargo for asymmetric dendrite growth and morphogenesis.
Proper growth of dendrites is critical to the formation of neuronal circuits, but the cellular machinery that directs the addition of membrane components to generate dendritic architecture remains obscure. Here, we demonstrate that post-Golgi membrane trafficking is polarized toward longer dendrites of hippocampal pyramidal neurons in vitro and toward apical dendrites in vivo. Small Golgi outposts partition selectively into longer dendrites and are excluded from axons. In dendrites, Golgi outposts concentrate at branchpoints where they engage in post-Golgi trafficking. Within the cell body, the Golgi apparatus orients toward the longest dendrite, and this Golgi polarity precedes asymmetric dendrite growth. Manipulations that selectively block post-Golgi trafficking halt dendrite growth in developing neurons and cause a shrinkage of dendrites in mature pyramidal neurons. Further, disruption of Golgi polarity produces neurons with symmetric dendritic arbors lacking a single longest principal dendrite. These results define a novel polarized organization of neuronal secretory trafficking and demonstrate a mechanistic link between directed membrane trafficking and asymmetric dendrite growth.
Horton
April C
AC
Department of Neurobiology, Duke University Medical Center, Durham, North Carolina 27710, USA.
Rácz
Bence
B
Monson
Eric E
EE
Lin
Anna L
AL
Weinberg
Richard J
RJ
Ehlers
Michael D
MD
D000818:Animals; D001369:Axons / Q000502:physiology; D016764:Cell Polarity / Q000502:physiology; D003712:Dendrites / Q000378:metabolism / Q000502:physiology*; D006056:Golgi Apparatus / Q000502:physiology; D007150:Immunohistochemistry; D008297:Male; D016253:Microscopy, Immunoelectron; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009474:Neurons / Q000502:physiology; D021381:Protein Transport / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley
D009419:Nerve Tissue Proteins