The stereotaxic approach of a target structure in the rodent brain requires sufficient theoretical knowledge on the specific locations of different brain regions. The stereotaxic atlas, a necessity in stereotaxic procedures, provides the layout of the rodent brain through theoretical coordinates for the implantation of cannulae, electrodes, and other instruments.

Given that an important element of the stereotaxic procedure is the accurate quantification of internal and external distances in preparation for rodent surgery, stereotaxic atlases provide the precise coordinates for particular brain regions along the three orthogonal planes. The three adjustable vernier screwdrivers in the stereotaxic apparatus, which deliver accurate quantification of distances, are moved along these three planes, namely–the anteroposterior (AP) axis, running from the anterior to the posterior part of the animal’s head; the mediolateral (ML) axis, running along the midline to the right or left side; and the dorsoventral (DV) axis, running from the surface of the skull to the brain’s interior.