Timothy M. Gomez, PhD
PhD, University of Minnesota
257 Bardeen Labs
470 N. Charter St.
Madison, WI 53706
Work in my laboratory focuses on the intracellular mechanisms that regulate growth cone motility and behavior. Growth cones are sensory-motor specializations at the tips of all growing axons and dendrites that detect and transduce extracellular cues into guided outgrowth. Great advances have been made in recent years in our understanding of the factors that contribute to guided axon extension. Many new classes of ligands and their receptors have been discovered and we are beginning to appreciate how growth cones integrate multiple extracellular stimuli and convert those signals into stereotyped behaviors.
Research in my laboratory combines a variety of fluorescent probe technologies with confocal and total internal reflection fluorescence (TIRF) microscopy to visualize the dynamic behavior of growth cones and assess their physiological responses during axon extension in vitro and guided outgrowth in the intact spinal cord. We use two model systems for our studies. First, we study spinal cord and retinal ganglion cell (RGC) neuron development using the African Clawed frog Xenopus Laevis due to the large size, rapid development, and ease of molecular and surgical manipulation of its embryos. Second, we are studying the development of human forebrain, motoneuron and RGCs using neurons derived from human induced pluripotent stem cells (iPSCs). Various gain and loss of function techniques are used to alter the physiology of growth cones both in vitro and in vivo. In addition, we are using iPSCs derived from human patients with various autism spectrum disorders.
Santiago-Medina M, Gregus KA, Nichol RH, O’Toole SM, Gomez TM. (2015) Regulation of ECM degradation and axon guidance by growth cone invadosomes. Development. 1;142(3):486-96. doi: 10.1242/dev.108266.
Gomez TM, Letourneau PC. (2014) Actin dynamics in growth cone motility and navigation. Journal of Neurochemistry. 129(2):221-34.
Doers ME, Musser MT, Nichol R, Berndt ER, Baker M, Gomez TM, Zhang SC, Abbeduto L, Bhattacharyya A. (2014) iPSC-derived forebrain neurons from FXS individuals show defects in initial neurite outgrowth. Stem Cells and Development. 1;23(15):1777-87.
Santiago-Medina M, Gregus KA, Gomez TM. (2013) PAK-PIX interactions regulate adhesion dynamics and membrane protrusion to control neurite outgrowth. Journal of Cell Science. Mar 1;126(Pt 5):1122-33.
Kerstein PC, Jacques-Fricke BT, Rengifo J, Mogen BJ, Williams JC, Gottlieb PA, Sachs F, Gomez TM. (2013) Mechanosensitive TRPC1 channels promote calpain proteolysis of talin to regulate spinal axon outgrowth. Journal of Neuroscience. J Neurosci. 2013 Jan 2;33(1):273-85.
Saengsawang W, Taylor KL, Lumbard DC, Mitok K, Price A, Pietila L, Gomez TM, Dent EW. (2013) CIP4 coordinates with phospholipids and actin-associated proteins to localize to the protruding edge and produce actin ribs and veils. Journal of Cell Science. Jun 1;126(Pt 11):2411-23.
Myers JP, Robles E, Ducharme-Smith A, Gomez TM. (2012) Focal adhesion kinase modulates Cdc42 activity downstream of positive and negative axon guidance cues. Jounral of Cell Science. Jun 15;125(Pt 12):2918-29.
Gomez TM. (2011) Pioneering studies on the mechanisms of neuronal morphogenesis. Developmental Neurobiology. Sep;71(9):780-4.
Myers JP, Santiago-Medina M, Gomez TM. (2011) Regulation of axonal outgrowth and pathfinding by integrin-ECM interactions. Developmental Neurobiology. Nov;71(11):901-23.