A method for removing the brain and spinal cord as one unit from adult mice and rats

To collect complete rodent spinal cord samples for histological analysis, researchers typically use a method that involves fixation of the carcass, followed by decapitation and removal of the vertebrae and the spinal cord. Researchers then decalcify, process and embed the spinal column in paraffin. When this method is used, the spinal cord retains its natural curvature, which may be undesirable to some investigators. The authors describe a methodology by which the entire spinal cord, with the brain attached, can be removed from a mouse or rat, set against a rigid support material and fixed perfectly straight. This allows for more precise sectioning and simplified histological analysis. Researchers can even create block preparations, each of which contains multiple spinal cord sections, so that they can compare anatomically matched sections. This procedure can also be used to obtain fresh spinal cord samples that are free of bone and can be frozen in optimal cutting temperature medium.