Trajectories of cholinergic pathways within the cerebral hemispheres of the human brain.

All sectors of the human cerebral cortex receive dense cholinergic input. The origin of this projection is located in the Ch4 cell group of the nucleus basalis of Meynert. However, very little is known about the location of the pathways which link the cholinergic neurons of the nucleus basalis to the human cerebral cortex.

Theoretical situation of brain white matter tracts evaluated by three-dimensional MRI.

An accurate knowledge of cerebral anatomy is important in order to evaluate the precise location of a cerebral lesion. Cortical structures are identified by knowledge of the adjacent gyri and sulci; however, white matter tracts are difficult to differentiate from one another due to the lack of clear anatomic landmarks. Therefore, even if MRI shows obvious white matter abnormalities, in some cases it is difficult accurately to localize the lesion.