Moving and Removing Axonal Mitochondria
Thomas L. Schwarz, PhD
F.M. Kirby Center for Neurobiology
Children’s Hospital, Boston
and Dept. of Neurobiology, Harvard Medical School
Location: Foege Auditorium, GNOM S060
seminar abstract: Mitochondria are dynamic organelles. In every cell they move and undergo fission and fusion. Their distribution and associations with the cytoskeleton change in response to many signals, including the mitotic cell cycle. In addition, because neurons look like no other cell in the organism, with axons of up to a meter in humans, mitochondrial motility is particularly crucial to the survival of the neuron. The neuron also needs to clear away damaged mitochondria efficiently wherever in the cell they may arise. Not surprisingly then, defects in the transport machinery of neurons and in their mechanisms for removing damaged mitochondria have been linked to several neurodegenerative diseases, including ALS and Parkinson’s disease. This talk will present the evidence for a motor/adaptor complex that is responsible for and regulates the movement of mitochondria and will discuss how that movement is regulated by the cell cycle, Ca++, and glucose. We will look at the operation of two proteins PINK1 and Parkin that are mutated in forms of Parkinson’s disease and examine how these proteins operate in axons to clear away damaged mitochondria that might otherwise compromise the health of the cell. Particularly in the case of mitophagy, we will consider the special challenges posed for neurons by their extended geometry and the difficulty of having a PINK1-dependent pathway operating far from the soma.
From body to brain: control of autonomic physiology by the sensory vagus nerve
Rui Chang, Ph.D.
Department of Cell Biology
Harvard Medical School
Cardiac, respiratory, and other autonomic functions are precisely controlled by the nervous system, yet many autonomic reflexes remain poorly characterized at a molecular and cellular level. The sensory vagus nerve is a major conduit between body and brain, and is critical for many autonomic physiology. Using a genetic approach, we molecularly deconstructed the vagus nerve, and successfully identified neuron populations that are critically involved in respiratory physiology and digestive functions. We further elucidated the molecular mechanism for lung inflation-mediated apnea. Together, these findings lay the groundwork for a molecular dissection of respiratory and gastrointestinal physiology.
Claudia Moreno, Ph.D.
Department of Physiology and Membrane Biology
School of Medicine
University of California, Davis
host: Stan Froehner
University of Washington
Dept of Physiology & Biophysics
host: Stan Froehner