Pcdhαc2 is required for axonal tiling and assembly of serotonergic circuitries in mice

Science. 2017 Apr 28;356(6336):406-411. doi: 10.1126/science.aal3231.


Serotonergic neurons project their axons pervasively throughout the brain and innervate various target fields in a space-filling manner, leading to tiled arrangements of their axon terminals to allow optimal allocation of serotonin among target neurons. Here we show that conditional deletion of the mouse protocadherin α (Pcdhα) gene cluster in serotonergic neurons disrupts local axonal tiling and global assembly of serotonergic circuitries and results in depression-like behaviors. Genetic dissection and expression profiling revealed that this role is specifically mediated by Pcdhαc2, which is the only Pcdhα isoform expressed in serotonergic neurons. We conclude that, in contrast to neurite self-avoidance, which requires single-cell identity mediated by Pcdh diversity, a single cell-type identity mediated by the common C-type Pcdh isoform is required for axonal tiling and assembly of serotonergic circuitries.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Axons / pathology*
  • Cadherins / genetics
  • Cadherins / physiology*
  • Depression / genetics*
  • Gene Deletion
  • Limbic System / metabolism
  • Mice
  • Mice, Mutant Strains
  • Multigene Family
  • Serotonergic Neurons / metabolism
  • Serotonergic Neurons / pathology*
  • Serotonin / metabolism*


  • Cadherins
  • Pcdhalphac2 protein, mouse
  • Serotonin