Meynert and the basal nucleus

Abstract

Meynert described the "loop of the peduncular foot" (Schlinge des Hirnschenkelfusses), and its ganglion (Ganglion der Hirnschenkelschlinge) and related them to Reil's Substantia innominata and Gratiolet's Ansa peduncularis, from which he apparently built up his findings. Koelliker renamed the ganglion with the eponymous designation Meynert'sches Basalganglion (Meynert's basal ganglion), a name which endures to the present day, and described its topographical spread in relation to neighboring structures. Meynert and Koelliker also described aspects of cell composition of the ganglion (or nucleus) with a better account of the latter. Both, together with Reil and Gratiolet, were the outstanding personalities of the 19th century who performed the pioneering studies on basal formations of the forebrain. After these works, a considerable body of research appeared in the 20th century, with a focus on Meynert's basal nucleus and related structures. The development of further knowledge about these structures revealed their great importance in the activity of the brain, as evidenced in both normal and pathological states.

Nucleus basalis of Meynert revisited: anatomy, history and differential involvement in Alzheimer’s and Parkinson’s disease

“…However, the SI that we commonly refer to is actually more poorly defined anatomically and is known as the SI of Reichert. This is an unlabelled area with no boundaries within Reichert’s human brain atlas from the 1850s [ 27 ]. This region has evolved to be known as the anterior perforated substance by Beccari and in a more modern human stereotaxic brain atlas by Schaltenbrand and Bailey simply as basalis to describe the sub-commissural region dorsal to the amygdala [ 88 ].…”

The anterior perforated substance (APS) revisited: Commented anatomical and imagenological views

“…The BGM was best described by Mesulam et al. ( 1983 ) (Arendt et al., 1983 ; Ayala, 1915 ; Brockhaus, 1942 ; Engelhardt, 2013 ; Haber et al., 1993 ; Hedreen et al., 1984 ; Jones et al., 1976 ; Liu et al., 2015 ; Mesulam & Ch, 1988 ; Mesulam et al., 1983, 1984 , 1986 ; Page & Sofroniew, 1996 ; Sakamoto et al., 1999 ; Simic et al., 1999 ; Tenenholz‐Greenberg & Heinsen, 2007 ). Two portions (Ch1 and Ch2) are septal, Ch1 at the medial septal nucleus, and Ch2 in the vertical limb of the diagonal band of Broca.…”

“…This allowed us to interpret the IRM tracks of the amygdalofugal way especially the IthP, and the ansa lenticularis without recurrence to tractography. The known relations of the grey substance with fibers, in part of old tradition (Ayala, 1915 ; Engelhardt, 2013 ), allowed us to recognize tissue of the basal ganglion associated with tracts, anterior commissure, medullary laminae, and putamen. Never most valuable von Gudden's dictum: “First anatomy.…”