Neurons in brains of one songbird species equipped with a built-in suicide program that kicks in at the end of the breeding season have been kept alive for seven days in live birds by researchers trying to understand the role that steroid hormones play in the growth and maintenance of the neural song system.
It is the first time scientists have shown that inhibiting an enzyme involved in programmed cell death can protect a brain region in a living animal from neurodegeneration following the withdrawal of steroids.
In addition, the University of Washington research being published in tomorrow's edition of the Journal of Neuroscience reports that the infusion of this enzyme inhibitor into one brain region also kept another connected brain structure from degenerating.
The research has potential to help scientists develop clinical strategies for treating strokes and such human age-related degenerative diseases as Alzheimer's, Parkinson's and dementia, all of which may involve the death of brain cells.
Previous work by the co-authors Christopher Thompson and Eliot Brenowitz showed that neurons in a brain region called the HVC begin regressing within 12 hours after the withdrawal of the steroid hormone testosterone, followed soon thereafter by cell death. The new study indicates that enzymes called caspases, which play a key role in a cell suicide process called apoptosis, are involved in this process of neurodegeneration and that inactivation of caspases protects brain cells for at least a week.
Thompson, who just earned his doctorate in neurobiology and behavior at the UW and is now a postdoctoral researcher at the Freie Univeristät in Berlin, and Brenowitz, a UW professor of psychology and biology, study the brain regions controlling the singing behavior of a white-crowned sparrows.
This work was also featured in "This Week in The Journal" in the Journal of Neuroscience. Yay me again.