A transcervical surgical approach to the ventral medulla of the cat

For the purpose of injection of anatomical tracers, it is desirable to have a surgical approach which provides the most direct approach to the target structure. This minimizes the amount of neural tissue that must be transgressed, and hence the leakage of tracer along the tract and the potential undesirable labelling that may result from this. In addition, visual guidance is preferable to stereotaxic guidance of injections where possible, particularly in situations where the target structure is far removed from the ear bar zero coordinate. Some of our work has necessitated small, discrete injections in the inferior olive sparing the adjacent reticular formation. The ventral transcervical approach to the medulla which was developed for this purpose is described below. It may conceivably be of use to physiologists wishing to record from ventral medullary structures. We feel it is a useful technique, but one which those with little surgical experience might not attempt. It is hoped that our description may guide others who could benefit by this approach.