Fig. 5: Fiber dissection from the caudal aspect and morphometry of the psalterium.

a Exposure of the splenium of the corpus callosum (SCC) and the quadrigeminal plate (QP) after bilateral removal of the medial aspects of the occipital lobes and the cerebellar apex. b Closer view on the SCC, the pineal gland (PG), and the superior (SC) and inferior colliculi (IC) with the corresponding brachia (brachium of the superior colliculus, Bsc; brachium of the inferior colliculus; Bic) c Dissection of the subcortical fibers of the right isthmus revealed the fibers of the forceps major (FM) as caudo-lateral continuation of the SCC. In addition, the cerebral peduncle (CPe), medial geniculate body (MGB) and lateral geniculate body (LGB) are exposed. d Posterior oblique view on the crus fornicis (crF), the choroidal fissure (FC), and the pulvinar (Pu) after opening the atrium (A). e Midline incision and removal of the right half of the SCC exposes the septum pellucidum (SP), velum interpositum (VI), the tapetum (Ta) passing over the A, the crF, and the choroid plexus (CP). f Another specimen after fenestration of the SCC and partial removal of the thalamus (Th) to visualize the A, crF and psalterium (Ps). g Separation and elevation of the medial part of the SCC from the Ps. The unification of the crF into the body of the fornix (bF) form the anterior border of the Ps. h The length (l) of the Ps was measured from the unification of the crF to form the bF to the SCC. The width (w) of the Ps was defined as the distance between right and left attachment of the crF to the SCC. Dissections: CS (A-E), KA (F-G), and NK (H).