Neural pathway from nucleus basalis of Meynert passing through the cingulum in the human brain

With the exception of post-mortem brain study, there has been no specific evaluation method for the nucleus basalis of Meynert (NBM) and its cholinergic pathway. In the current study, we attempted to identify the neural pathway from the NBM passing through the cingulum in the human brain, using diffusion tensor tractography (DTT). We recruited 22 healthy volunteers for this study. Diffusion tensor images (DTIs) were scanned using 1.5-T; images of the neural pathway from the NBM passing through the cingulum were obtained using the FMRIB Software Library (FSL). Values for fractional anisotropy (FA), mean diffusivity (MD), and tract volume were measured for the neural pathway. The neural pathway, which originated from the NBM, entered the cingulum, running to the anterior portion of the genu of the corpus callosum in the anterior, superior, and lateral directions. The rest of the pathway was through the cingulum to the splenium, or posteriorly to the retrosplenial area. In terms of fractional anisotropy, mean diffusivity, or tract volume, there were no significant differences between hemispheres (P > 0.05). Using a probabilistic tractography technique, we identified the neural pathway from the NBM passing through the cingulum in the human brain. Methodology and data from this study of the neural pathway from the NBM passing through the cingulum will be helpful in elucidation of the pathology of diseases involving the basal forebrain or frontal lobe.