Correction to: Lab Animal https://doi.org/10.1038/s41684-020-0623-0, published online 12 August 2020.

In the version of this article initially published, in the section ‘To the depths,’ the value for a wavelength was incorrect. In the sentence ‘Whereas confocals emit visible wavelengths of light, 2P systems extend the wavelength to between 9000 and 1000 nm, which reduces scattering and makes the brain appear more transparent,’ the number 9000 should have been 900. The error has been corrected in the HTML and PDF versions of the article.