Abstract: A rotational adaptor is provided for use with a stereotaxic instrument used in brain research to hold and stabilize the head of a small animal, such as a rat, having a cradle with two ear bars and a nose clamp wherein the cradle may be rotated while maintaining support of the animal's head by the ear bars and the nose clamp. The device allows electrodes and micropipettes to be implanted through the side of the skull as well as through the top of the skull, increasing the number of available implant pathways and consequently reducing trauma experienced by the animal.

Abstract: A drill press is provided for use in conjunction with a three dimensional stereotaxic manipulator. The drill press includes a body carried by a movable member of the manipulator wherein the body has upper and lower segments and at least one guide shaft extending between the segments. A slide which carries a drill for forming skull openings is driven by a dial cord drive. The dial cord extends around a drive shaft so that rotation of the drive shaft by a handle causes the slide to move upwardly and downwardly to safely and quickly accomplish the formation of a skull opening in a small animal typically used in brain research.