This article is a commentary on:
Long-term channelrhodopsin-2 (ChR2) expression can induce abnormal axonal morphology and targeting in cerebral cortex
A commentary on
Long-term channelrhodopsin-2 (ChR2) expression can induce abnormal axonal morphology and targeting in cerebral cortex
by Miyashita, T., Shao, Y. R., Chung, J., Pourzia, O., and Feldman, D. E. (2013). Front. Neural Circuits 7:8. doi: 10.3389/fncir.2013.00008
In our recent paper (Miyashita et al., 2013), we showed that long-term, high-level channelrhodopsin-2 (ChR2) expression by in utero electroporation (IUE) produces structural abnormalities in the axons of ChR2-expressing pyramidal cells in rat somatosensory cortex. In the Discussion of our paper, we mentioned that such abnormalities were not observed in an earlier study using long-term IUE of ChR2 under the same promoter (Huber et al., 2008). A methodological difference has been brought to our attention that likely explains this difference. Huber et al. expressed wildtype ChR2 (Chop2-315 from Nagel et al., 2003), while we expressed hChR2 that was codon-optimized for higher mammalian expression (Zhang et al., 2006). This suggests that lower ChR2 protein levels in the Huber study may have enabled long-term expression without axonal malformations. This further supports our main conclusion that morphological abnormalities are associated with high-level, long-term expression of ChR2 protein, and that lower level expression is necessary for long-term studies.
References
Huber, D., Petreanu, L., Ghitani, N., Ranade, S., Hromádka, T., Mainen, Z., et al. (2008). Sparse optical microstimulation in barrel cortex drives learned behaviour in freely moving mice. Nature 451, 61–64.
Miyashita, T., Shao, Y. R., Chung, J., Pourzia, O., and Feldman, D. E. (2013). Long-term channelrhodopsin-2 (ChR2) expression can induce abnormal axonal morphology and targeting in cerebral cortex. Front. Neural Circuits 7:8. doi: 10.3389/fncir.2013.00008
Nagel, G., Szellas, T., Huhn, W., Kateriya, S., Adeishvili, N., Berthold, P., et al. (2003). Channelrhodopsin-2, a directly light-gated cation-selective membrane channel. Proc. Natl. Acad. Sci. U.S.A. 100, 13940–13945.
Citation: Miyashita T, Shao YR, Chung J, Pourzia O and Feldman DE (2013) Corrigendum: Long-term channelrhodopsin-2 (ChR2) expression can induce abnormal axonal morphology and targeting in cerebral cortex. Front. Neural Circuits 7:45. doi: 10.3389/fncir.2013.00045
Received: 15 February 2013; Accepted: 04 March 2013;
Published online: 20 March 2013.
Edited by:
Charles F. Stevens, The Salk Institute for Biological Studies, USAReviewed by:
Charles F. Stevens, The Salk Institute for Biological Studies, USACopyright © 2013 Miyashita, Shao, Chung, Pourzia and Feldman. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc.
*Correspondence: dfeldman@berkeley.edu