Axonal terminations in reuniens from A25, amygdala, and hippocampus. A, Normalized A25 space depicts location of injection sites (black) used to map axonal terminations. Case BR features a posterior medial injection site; case BU features an anterior orbital injection site. Dashed lines depict areal boundaries. B, Medial surface (case BR). Lines depict planes of cut for sections seen in C. C, Individual axons traced in RE depict the termination pattern (case BR) from rostral levels (left, dark gray) to caudal levels (light gray). D, Stereologic density of axonal terminations from rostral (left) to caudal (right) RE sections (case BR). E–G, Organization as above, but for case BU in A25. H, Normalized amygdala space depicts location of injection sites (black) used to map axonal terminations. One case (BT) featured an injection in the basomedial (also known as accessory basal) and ventral medial sector of the basolateral nucleus. The other case (BM) featured an injection in the ventral medial sector of the basolateral nucleus. I–K, Organization as above, but for case BT in amygdala. L–N, As above, but for case BM in amygdala. O, Injection site (black) in the hippocampus (case BT) used to map axonal terminations after tracer injection in CA3, DG, and CA1. P–R, As above, but for case BT in hippocampus. S, Injection site (black) in the hippocampus (case BQ) used to map axonal terminations after tracer injection in CA1, DG, prosubiculum, and subiculum. T–V, As above, but for case BQ in hippocampus. AON, Anterior olfactory nucleus; BL, basolateral nucleus of amygdala; BM, basomedial nucleus of the amygdala; C, caudal; CA, cornu ammonis; Ce, central nucleus of the amygdala; cg, cingulate sulcus; Co, cortical nucleus of the amygdala; D, dorsal; DG, dentate gyrus; Ent, entorhinal cortex; III, third ventricle; IM, intercalated masses of the amygdala; L, lateral; La, lateral nucleus of the amygdala; lo, lateral orbital sulcus; M, medial; Me, medial nucleus of amygdala; mo, medial orbital sulcus; MPAll, medial periallocortex; OPAll, orbital periallocortex (agranular); OPro, orbital proisocortex (dysgranular); OPT, optic tract; PLBL, paralaminar basolateral nucleus of the amygdala; ProS, prosubiculum; R, rostral; Sub, subiculum; V, ventral.