Fig. (3). Red nucleus A) Normal structure in a control case (male, aged 4 months). Below, higher magnification of the encircled area in the upper image with large neurons of the caudal magnocellular portion.B) Hypoplasia in a case of SIDS (male, aged 3 months). Below, higher magnification of the encircled area in the upper image with lack of large neurons that are typical of the caudal magnocellular portion.Klüver-Barrera stain. Magnification: in the upper images 4x; below 10x.