Upcoming ION Seminars
Abstract:
To maintain a functional mitochondrial population in a long-lived cell like a neuron, mitochondria must be continuously replenished through the process of mitochondrial biogenesis. Because the majority of mitochondrial proteins are nuclear encoded, mitochondrial biogenesis requires communication between mitochondria and the nucleus. This can be a challenge in a large, compartmentalized cell like a neuron in which a large portion of the mitochondrial population is in neuronal compartments far from the nucleus. Using in vivo assessments of mitochondrial biogenesis in zebrafish neurons, we determined that mitochondrial transport between distal axonal compartments and the cell body is required for sustained mitochondrial biogenesis. Estrogen-related receptor transcriptional activation links transport with nuclear expression of mitochondrial genes. New data suggests this regulation supports cell body based and local mitochondrial biogenesis at the synapse which we hypothesize work together to support distal mitochondrial populations. Together, our data support a role for retrograde feedback between axonal mitochondria and the nucleus for regulation of mitochondrial biogenesis in neurons.
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The goal of research in the Sawtell laboratory is to forge detailed links between the properties of neural circuits and their functions. Our studies of weakly electric fish have shown how a specific form of synaptic plasticity operating within a well-characterized cerebellum-like circuit functions to predict and cancel out sensory inputs generated by the animal’s own behavior. Such a process could allow behaviorally relevant sensory inputs, e.g. those generated by predators or prey, to be processed more effectively. This work provides a mechanistic account of how copies of motor commands are transformed into specific predictions of sensory events as well as insights into the function of the cerebellar granular layer. A tight coordination of experimental and theoretical approaches is a key aspect of the lab’s approach. Experimental work involves intra- and extracellular recordings from identified neuron classes in awake, behaving fish. Theoretical work is performed in collaboration with Larry Abbott’s group at the Center for Theoretical Neuroscience at Columbia University.
Abstract: Sensory hair cells transmit auditory and vestibular information to the brain. While many forms of hearing loss result from hair cell death, increasing evidence shows that noise-induced and age-related hearing loss often stem from synaptic damage. Restoring hearing in these cases will require rebuilding synaptic connections, which depends on understanding how sensory synapses form and function in vivo. Our work combines genetics, CRISPR-based mutagenesis, and live imaging in zebrafish neuromast hair cells to define the molecular and activity-dependent mechanisms that drive synapse formation, function, and regeneration. By visualizing synapses in a live, transparent system, we aim to uncover principles that guide the restoration of hair cells and their synaptic connections after damage.
Seminar Details
This academic year will host a series of virtual and in person seminars with live, remote access via Zoom. ION Seminars are open to the University of Oregon community and in person attendance is welcome. In person seminars will be held in Willamette 110 at 4 PM PT.
To accommodate remote speakers and time differences, some seminars may be offered at Noon PT or another agreed upon time. For students taking BI 407/507 Neuroscience Seminar please contact the course instructor to access recordings as needed.
Details for upcoming seminars will be shared here on the ION website as well as through our ION mailing lists. Links for remote access via Zoom will be available only through ION Seminar mailing list and those not on the list can request access by contacting Jenna Penny with their uoregon.edu email address.