April 12, 2007
Two Researchers Work to Unravel Mysteries of the Aging Brain
Americans are living longer thanks to advances in treating major diseases, but the new longevity exposes them to a greater threat to the aging brain’s vulnerability to degenerative disorders.
Two Northwestern University researchers working to unravel the mysteries of neurodegenerative disorders and their threat to health and the quality of lives are Catherine S. Woolley, PhD, and Mark D. Bevan, PhD.
Dr. Woolley, professor of neurobiology and physiology in the Weinberg College of Arts and Sciences, has been using reproductive hormones as tools to understand brain plasticity and brain function. Laboratory testing on rats has shown that the female sex hormone estrogen increases the number and complexity of the synaptic connections in the hippocampus, suggesting that the hormone can help protect the brain from degeneration.
Her research opens doors to deeper understanding of many diseases, including Alzheimer’s and epilepsy. Her newest research studies the effects of addiction on the brain’s neural circuitry. Dr. Woolley’s experiments prepare the way to finding drugs that mimic estrogen’s neuroprotective benefits without activating all of its hormonal effects and that can be used on both men and women.
Dr. Woolley’s work is funded by the National Institutes of Health’s National Institute on Drug Abuse and the National Institute on Neurological Disorders and Stroke (NINDS). She was also the first Northwestern faculty member to be awarded the W.M. Keck Foundation Award for Distinguished Young Scholars in Medical Research, which she received in 2002.
Dr. Bevan, professor of physiology at the Feinberg School of Medicine, and his laboratory study the brain’s basal ganglia and their dysfunction in movement disorders such as Parkinson’s disease (PD). The researchers utilize a combination of electrophysiology, two-photon imaging, and electron microscopy.
Normal neuronal activity in the basal ganglia is arrhythmic, poorly correlated, and related to movement in a highly complex manner. In PD, neuronal activity is strongly correlated, and low-frequency rhythms develop that are associated with the disease’s characteristic tremor and other motor symptoms. Dr. Bevan’s strategy for understanding this transformation has been to first determine the principles underlying normal neuronal activity and then determine how dopamine depletion in PD generates the pathological activity pattern.
One recent therapy for PD is deep brain stimulation of the subthalamic nucleus, which greatly ameliorates the symptoms of PD. Dr. Bevan hopes that greater understanding of the mechanisms underlying the therapeutic efficacy of this treatment will facilitate the discovery of pharmaceutical or other nonsurgical treatments that are associated with less risk to the patient.
His laboratory is funded by NINDS and the National Parkinson Foundation and forms part of Northwestern University’s Morris K. Udall Center of Excellence for Parkinson’s Disease Research.
(Adapted from an article in the Office for Research Annual Report 2006)