The Vollum comprises a vibrant and diverse scientific community focused on understanding fundamental biological mechanisms. Learn about our faculty & labs
The Vollum Institute is a privately endowed research institute at Oregon Health & Science University dedicated to basic research that will lead to new treatments for neurological and psychiatric diseases. Vollum scientists have broad-ranging interests that coalesce around molecular neurobiology and cellular physiology. Their work has transformed the field of neuroscience and, in particular, have provided important advances in the study of synaptic transmission, neuronal development, neurotransmitter transporters, ion channels and the neurobiology of disease.
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More about Dr. Freeman's research
Glia are cells in the brain that were long thought to be "helpers" that support neurons to perform their functions. Dr. Freeman has shown that the most predominant and least-studied glial cell, the star-shaped astrocyte, is essential to the brain's signaling network and allows for many complex behavioral outputs. His research has shown that neuromodulators, a messenger that regulates a diverse group of neurons, function not only through neurons, but signal through astrocytes as well. Currently, his research explores how neurons and glia cells communicate with one another so the nervous system runs smoothly and how their dysfunction can result in neurological disease.
Axons, slender nerve fibers, must remain intact to function, and, in cases of injury or disease, they break. His research team exploited the unique set of genetic tools available in fruit flies to label specific subsets of neurons in the intact animal, cut axons to induce degeneration, and then systematically broke each gene in the fly genome to determine which were required to promote axon destruction. They discovered that when dSarm/Sarm1 was deleted it completely blocked axon degeneration, and went on to show the same was true in mice and human cell lines. Remarkably, Freeman and colleagues have recently found that blocking the Sarm1 pathway alleviates nearly all pathological effects of traumatic brain injury in mice, and other labs have implicated Sarm1 signaling in peripheral neuropathy. These findings indicate that if researchers can find a way to block the genes that drive degeneration after injury—something Freeman's lab is currently pursuing—there's an opportunity to save the nervous system from degeneration in many cases of injury or neurodegenerative disease.
NMDA receptors (NMDAR) play a central role in chemical neurotransmission where the prevalent receptor assembly has two identical glycine-binding subunits and two distinct glutamate binding subunits. To determine how the incorporation of two different GluN2 subunits alters receptor symmetry and subunit-subunit interactions, scientists in the Gouaux Lab resolved the structure of the GluN1/GluN2A/GluN2B receptor by single particle cryo-EM. The lab's research revealing the architecture of the triheteromeric NMDA receptor complex was published online Feb. 23 in the journal Science.
Read the abstract in PubMed
A team of scientists, led by Marc Freeman at the Vollum Institute and Mary Logan at the Jungers Center for Neurosciences Research, recently identified a gene, TRAF4, which provides important information about the signaling pathways that spur glial cells to recognize and clear degenerating axons. The research was published online Feb. 6 in the journal Nature Communications. Co-authors include Tsai-Yi Lu at Johns Hopkins University and Jennifer MacDonald, Lukas Neukomm, Amy Sheehan and Rachel Bradshaw from the University of Massachusetts Medical School.
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Read the abstract in PubMed
Cholinergic interneurons underlie spontaneous dopamine release in nucleus accumbens
Jordan T. Yorgason, Douglas M. Zeppenfeld and John T. Williams
The Journal of Neuroscience, 2017 Feb 22; 37(8):2086-2096
A gradient in synaptic strength and plasticity among motoneurons provides a peripheral mechanism for locomotor control
Wei-Chun Wang and Paul Brehm
Current Biology, 2017 Feb 6; 27(3):415-422
Phosphorylation of Rap1 by cAMP-dependent protein kinase (PKA) creates a binding site for KSR to sustain ERK activation by cAMP
Maho Takahashi, Yanping Li, Tara J. Dillon and Philip J.S. Stork
The Journal of Biological Chemistry, 2017 Jan 27; 292(4):1449-1461