Rat stereotaxic surgery without earbars.

Described here is a rat headholding device intended for use in stereotaxic surgery. The assembly consists of a mouthpiece that accommodates the upper incisors and fits against the lateral and occlusive surfaces of the upper molars and of a contoured extension that is clamped down against the snout. To determine whether the apparatus could provide adequate stereotaxic support, we compared measures of skull displacement during surgery when using the "snoutclamp" and when using conventional earbars. Although the snoutclamp did not hold the head as rigidly as the earbar assembly did, the loss of accuracy was small. We judge that the snoutclamp can be used effectively as an alternative headholding device for many applications of stereotaxic surgery.