Photomicrographs of the dorsal portion of the amygdala of the macaque monkey. (A) Nissl-stained section of the dorsolateral portion of the amygdala. Much of the field is taken up by the central nucleus that can be divided into lateral (CEl) and medial (CEm)divisions. The basal nucleus (B) is located just ventral to the central nucleus. The substantia innominata (SI) is located just dorsal to the central nucleus. (B) Immunohistochemical staining of the amygdala using plasma from a representative child with autism. Labeled neurons are observed throughout all nuclei of the amygdala. In the central nucleus, the lateral nucleus has relatively few labeled neurons, whereas the density, size and dendritic staining of cells is much more prominent in the medial portion of the central nucleus. Calibration bar, 250 μm.