The results were striking. In frontotemporal dementia, there was early, severe and selective loss of von Economo neurons compared to control subjects. In Alzheimer's disease, von Economo neurons were not significantly depleted.
"This finding provides new insight into how frontotemporal dementia erodes the brain at the cellular level," says the first author of the study, William Seeley, MD, UCSF instructor of neurology and a clinician-scientist at the UCSF Memory and Aging Center.
Progress has been made in illuminating some of the genetic and molecular aspects of the disease ?two mutated genes are associated with most inherited forms of the disease and major misprocessed proteins have been identified ?but "discoveries at the genetic and molecular level do not yet explain why specific populations of neurons are dying," he says.
"This observation gives us a new window into the early and cell-specific degenerative process, and we can use this window to better understand disease pathogenesis."
The team, led by Seeley, is currently trying to study von Economo neuron-rich regions in living patients using neuroimaging. They also are studying VENs, themselves, in autopsy studies using neuropathological techniques.
As FTD is a disease for which there is as yet no disease-modifying therapy, studies of von Economo neurons could provide new strategies.
Why the cells are vulnerable is still a mystery, says Seeley. But given the fact that they are evolutionarily new, the explanation may be that there are still "kinks" in the genetic programming of the neuronal circuits.
"VENs probably help us in some wonderful way, which would explai
Source:University of California - San Francisco