July 2, 2009

Memory decline reversed in mouse model

U.S. scientists say a human growth factor used to stimulate blood stem cells to proliferate in bone marrow can also reverse memory impairment in mice.

Researchers at the University of South Florida and Haley Hospital, both in Tampa, Fla., genetically altered mice to develop Alzheimer's disease. The scientists found the growth factor -- granulocyte-colony stimulating factor -- significantly reduced levels of the brain-clogging protein beta amyloid found in abundance in the brains of the Alzheimer's mice, and also increased production of new neurons and promoted nerve cell connections.

GCSF has been used and studied clinically for a long time, but we're the first group to apply it to Alzheimer's disease, said Dr. Juan Sanchez-Ramos, the study's lead author. This growth factor could potentially provide a powerful new therapy for Alzheimer's disease -- one that may actually reverse disease, not just alleviate symptoms like currently available drugs.

The researchers said injections under the skin of filgrastim (Neupogen) -- one of three commercially available GCSF compounds -- mobilized stem cells leading to improved memory and learning behavior in the Alzheimer's mice.

The beauty in this less invasive approach is that it obviates the need for neurosurgery to transplant stem cells into the brain, Sanchez-Ramos said.

The findings are reported online in the journal Neuroscience and will appear in the journal's August print edition.