Rodent Studies Focus on Parkinson's Treatments

Research adds to findings on dorsal column stimulation, deep brain stimulation

23 mar 2009-- Dorsal column stimulation in animal models of Parkinson's disease points to a less-invasive method of improving function, and the use of optogenetics suggests a major target for deep brain stimulation in the disease, according to two studies published March 20 and online March 19 in Science.

In the first study, Romulo Fuentes, Ph.D., of the Duke University Medical Center in Durham, N.C., and colleagues analyzed data from pharmacologically induced dopamine-depleted mice that underwent dorsal column stimulation (DCS) above the spinal cord at the upper thoracic level. The mice displayed greater locomotion during stimulation, particularly at 300-Hz. DCS also led to increased locomotion in rats with bilateral 6-hydroxydopamine lesions.

In the other study, Viviana Gradinaru of Stanford University in Stanford, Calif., and colleagues discuss the use of optogenetics and solid-state optics to influence different circuit elements in rodent models of Parkinson's disease. The authors found that frequency-dependent effects on afferents to the subthalamic nucleus region appeared to be a direct target of deep brain stimulation in Parkinson's disease.

"In parallel with the behavioral improvements, DCS shifted activity patterns in the primary motor cortex and in the dorsolateral striatum into a state closely resembling that found before and during spontaneous initiation of locomotion in normal and depleted animals. This suggests that DCS helps motor-related brain areas shift into a state permissive of the initiation of movements," write Fuentes and colleagues.

Several authors of the second study are supported by a number of foundations.

Abstract - Fuentes
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Abstract - Gradinaru
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