After 50 or so years of dopamine theory, PD proves more illusive.
Imad

Parallel brainstem circuit discovery suggests new path in Parkinson's research
Chicago and Montreal researchers studying the lowly lamprey eel have identified an overlooked nervous system pathway running parallel to known brainstem locomotor command circuitry in vertebrates such as birds, fishes and mammals.

The finding is reported in Nature Neuroscience, online May 16, and highlighted in the magazine's "news and views" section.

Simon Alford, University of Illinois at Chicago professor of biological sciences and the article's corresponding author, said the role of a neurotransmitter associated with this parallel pathway may also suggest new research directions for treating Parkinson's disease.

Alford, along with his former graduate student and lead author Roy Smetana, now a University of Pittsburgh resident in psychiatry, worked with Université de Montréal and Université de Québec à Montréal neurobiologist Réjean Dubuc and his post-doctoral researcher Laurent Juvin in trying to sort out how the neurotransmitter analog muscarine modifies sensory information going to the brain.

Their work determined that muscarine stimulated neural activity, leading to locomotion in the laboratory lampreys.

The group focused its attention on a collection of brainstem neurons that tell the spinal cord to generate motor output that enables walking and other locomotion.

"We started looking at this group of neurons, which in the lamprey are conveniently very large, so they're easy to plant electrodes and record from," said Alford. "We discovered the muscarinic excitation was not working on these cells, but on a previously unknown group of cells within the brainstem."