Discrepancies in stereotaxic coordinate publications and improving precision using an animal-specific atlas.

Rodent brain atlases have traditionally been used to identify brain structures in three-dimensional space for a variety of stereotaxic procedures. As neuroscience becomes increasingly sophisticated, higher levels of precision and consistency are needed. Observations of various atlases currently in use across labs reveal numerous coordinate discrepancies. Here we provide examples of inconsistencies by comparing the coordinates of the boundaries of various brain structures across six atlas publications. We conclude that the coordinates determined by any particular atlas should be considered as only a first approximation of the actual target coordinates for the experimental animal for a particular study. Furthermore, the coordinates determined by one research team cannot be assumed to be universally applicable and accurate in other experimental settings. To optimize precision, we describe a simple protocol for the construction of a customized atlas that is specific to the surgical approach and to the species, gender, and age of the animal used in any given study.