TY - JOUR
TI - Dissecting the default mode network: Direct structural evidence on the morphology and axonal connectivity of the fifth component of the cingulum bundle
AU - Skandalakis, G.P.
AU - Komaitis, S.
AU - Kalyvas, A.
AU - Lani, E.
AU - Kontrafouri, C.
AU - Drosos, E.
AU - Liakos, F.
AU - Piagkou, M.
AU - Placantonakis, D.G.
AU - Golfinos, J.G.
AU - Fountas, K.N.
AU - Kapsalaki, E.Z.
AU - Hadjipanayis, C.G.
AU - Stranjalis, G.
AU - Koutsarnakis, C.
JO - EGYPTIAN JOURNAL OF NEUROSURGERY
PY - 2021
VL - 134
TODO - 4
SP - 1334-1345
PB - American Association of Neurological Surgeons
SN - null
TODO - 10.3171/2020.2.JNS193177
TODO - article;  axon;  cingulum (brain);  default mode network;  fusiform face area;  human;  human experiment;  medial temporal lobe;  microdissection;  neurosurgeon;  parahippocampal place area;  parieto-occipital sulcus;  perirhinal cortex;  precuneus;  pyriform cortex;  runner;  white matter;  anatomy and histology;  autopsy;  brain mapping;  cadaver;  cytology;  default mode network;  diffusion tensor imaging;  frontal lobe;  nerve cell network;  nerve fiber;  nerve tract;  parietal lobe;  physiology;  temporal lobe;  tissue fixation, axon, Autopsy;  Axons;  Brain Mapping;  Cadaver;  Default Mode Network;  Diffusion Tensor Imaging;  Frontal Lobe;  Humans;  Microdissection;  Nerve Fibers;  Nerve Net;  Neural Pathways;  Parietal Lobe;  Temporal Lobe;  Tissue Fixation;  White Matter
TODO - OBJECTIVE Although a growing body of data support the functional connectivity between the precuneus and the medial temporal lobe during states of resting consciousness as well as during a diverse array of higher-order functions, direct structural evidence on this subcortical circuitry is scarce. Here, the authors investigate the very existence, anatomical consistency, morphology, and spatial relationships of the cingulum bundle V (CB-V), a fiber tract that has been reported to reside close to the inferior arm of the cingulum (CingI). METHODS Fifteen normal, formalin-fixed cerebral hemispheres from adults were treated with Klingler's method and subsequently investigated through the fiber microdissection technique in a medial to lateral direction. RESULTS A distinct group of fibers is invariably identified in the subcortical territory of the posteromedial cortex, connecting the precuneus and the medial temporal lobe. This tract follows the trajectory of the parietooccipital sulcus in a close spatial relationship with the CingI and the sledge runner fasciculus. It extends inferiorly to the parahippocampal place area and retrosplenial complex area, followed by a lateral curve to terminate toward the fusiform face area (Brodmann area [BA] 37) and lateral piriform area (BA35). Taking into account the aforementioned subcortical architecture, the CB-V allegedly participates as a major subcortical stream within the default mode network, possibly subserving the transfer of multimodal cues relevant to visuospatial, facial, and mnemonic information to the precuneal hub. Although robust clinical evidence on the functional role of this stream is lacking, the modern neurosurgeon should be aware of this tract when manipulating cerebral areas en route to lesions residing in or around the ventricular trigone. CONCLUSIONS Through the fiber microdissection technique, the authors were able to provide original, direct structural evidence on the existence, morphology, axonal connectivity, and correlative anatomy of what proved to be a discrete white matter pathway, previously described as the CB-V, connecting the precuneus and medial temporal lobe. © 2021 American Association of Neurological Surgeons. All rights reserved.
ER -