Stereotaxic surgery has been an invaluable tool in systems neuroscience, applied in many experiments for the creation of site-targeted lesions, injection of anatomical tracers or implantation of electrodes or microdialysis probes. In this protocol, we describe stereotaxic surgery optimized for gene delivery by recombinant adeno-associated viruses and lentiviruses in mice and rats. This method allows the manipulation of gene expression in the rodent brain with excellent spatiotemporal control; essentially any brain region of choice can be targeted and cells (or a subpopulation of cells) in that region can be stably genetically altered at any postnatal developmental stage up to adulthood. Many aspects of the method, its versatility, ease of application and high reproducibility, make it an attractive approach for studying genetic, cellular and circuit functions in the brain. The entire protocol can be completed in 1–2 hours.

NOTE: In the PDF version of this article initially published online, several lines of text were omitted. The last sentence on page 3167 (“Another well suited application is the use of recombinant viruses for anatomical tracing;”) should have been followed by “for example, simply labeling the entire axonal arborization with GFP27. Finally, in vivo cellular analysis of virally infected and manipulated cortical cells is possible in anesthetized rats and mice with the two-photon targeted-patching technique28–30. As for the study of gene function in behavior, several groups have used viral vectors to infect specific brains regions in mice, such as the midbrain ventral tegmental area and lateral amygdala, and have demonstrated distinct behavioral phenotypes31,32. The main advantage of this approach lies in the exceptional spatiotemporal control over the induced genetic manipulation, which avoids the confounding variables, such as gene alterations during early development and/or in multiple brain regions, typically associated with traditional mouse genetics.” The error has been corrected in the PDF version of the article.