Visualization of cortical projection neurons with retrograde TET-off lentiviral vector

PLoS One. 2012;7(10):e46157. doi: 10.1371/journal.pone.0046157. Epub 2012 Oct 5.


We are interested in identifying and characterizing various projection neurons that constitute the neocortical circuit. For this purpose, we developed a novel lentiviral vector that carries the tetracycline transactivator (tTA) and the transgene under the TET Responsive Element promoter (TRE) on a single backbone. By pseudotyping such a vector with modified rabies G-protein, we were able to express palmitoylated-GFP (palGFP) or turboFP635 (RFP) in corticothalamic, corticocortical, and corticopontine neurons of mice. The high-level expression of the transgene achieved by the TET-Off system enabled us to observe characteristic elaboration of neuronal processes for each cell type. At higher magnification, we were able to observe fine structures such as boutons and spines as well. We also injected our retrograde TET-Off vector to the marmoset cortex and proved that it can be used to label the long-distance cortical connectivity of millimeter scale. In conclusion, our novel retrograde tracer provides an attractive option to investigate the morphologies of identified cortical projection neurons of various species.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cerebral Cortex / cytology*
  • Fluorescent Dyes
  • Genetic Vectors*
  • Green Fluorescent Proteins / genetics
  • Lentivirus / genetics*
  • Mice
  • Neurons / cytology*
  • Promoter Regions, Genetic
  • Repressor Proteins / genetics*
  • Transgenes


  • Fluorescent Dyes
  • Repressor Proteins
  • tetracycline resistance-encoding transposon repressor protein
  • Green Fluorescent Proteins

Grants and funding

This study is the result of “Highly Creative Animal Model Development for Brain Sciences” carried out under the Strategic Research Program for Brain Sciences by the Ministry of Education, Culture, Sports, Science and Technology of Japan. Also supported by Scientific Research on Innovative Areas (Neocortical Organization) (22123009 to TY and 23123510 to HH) and the grant from the JSPS (Japan Society for the Promotion of Science) to AW (KAKENHI19500304 and 22500300), and Grants-in-Aid for Scientific Research A (20240030) to TY. Supported by WAKATE and KIBAN grants from the JSPS to HB and HO, respectively. Takashi Kawashima is a JSPS predoctoral fellow.