Question: where is the white matter located in the brain

title: White matter
text: A 2009 paper by Jan Scholz and colleagues used diffusion tensor imaging ( DTI ) to demonstrate changes in white matter volume as a result of learning a new motor task ( e.g. juggling ) . The study is important as the first paper to correlate motor learning with white matter changes . Previously , many researchers had considered this type of learning to be exclusively mediated by dendrites , which are not present in white matter . The authors suggest that electrical activity in axons may regulate myelination in axons . Or , gross changes in the diameter or packing density of the axon might cause the change . A more recent DTI study by Sampaio - Baptista and colleagues reported changes in white matter with motor learning along with increases in myelination .