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Biochemistry and Molecular Biology

Tamily Weissman-Unni

Associate Professor of Biology

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Biology-Psychology Hall


Biology 151: Genetics & Evolution with laboratory
Biology/Psychology 252: Introduction to Neuroscience
Biology 422: Neurobiology with laboratory
Biology 490: Neuroanatomically Correct (Brain Structure & Function)


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My lab is interested in the neural circuitry that underlies behavior. Specifically, how does connectivity develop in the young brain and how do mature connections generate behavior?

Brain function relies upon the precise organization of many neural circuits. Although we are beginning to understand important properties of simple circuits, we know little about how complex circuits form and how their mature properties underlie behavior. This is largely because the complexity of most brain circuits prevents their complete examination using traditional labeling or recording methods. Due to the generation of a new powerful approach (“Brainbow”), we can now label populations of cells in many different colors, allowing us to visualize multiple individual components of a complex circuit in unprecedented detail. We have applied this approach to the translucent developing zebrafish nervous system, where individual synapses can be visualized over time within the living animal. Using this combined approach, we are testing how an important circuit within the cerebellum, the mossy fiber-to-granule cell synapse, develops and functions.  These studies, along with dynamic imaging and recording of neuronal activity, will allow us to quantify the developmental circuit properties of a complex pathway and begin to determine what types of information are being compared in this pathway to generate appropriate behavior. The combination of two powerful approaches – Brainbow and zebrafish – allows us to ask these detailed questions about a complex circuit in the brain of a living, intact animal.

Our long-term goals are to understand how complex circuits develop and function in the brain. On a broader scale, we hope to shed light upon how the brain controls behavior and how this process can go awry in human disease. There are certain human disorders that arise when normal cerebellar development goes wrong (for example, in childhood cerebellar ataxias).  Future directions in the lab will investigate how cerebellar circuits may be perturbed in transgenic zebrafish lines that model human ataxia.  A better understanding of normal and abnormal cerebellar circuitry will help broaden our understanding of these diseases, and of the important role that the cerebellum plays in human behavior.

Publications (* indicates undergraduate author)

  • Marra MH, *Tobias ZJC, *Cohen HR, Glover G, Weissman TA.  In vivo time-lapse imaging in the zebrafish lateral line: A flexible, open-ended research project for an undergraduate neurobiology laboratory course.  Journal for Undergraduate Neuroscience Education, 2015 Jul 7;13(3):A215-24. eCollection 2015 Summer.
  • Weissman TA , Pan YA. Brainbow: New resources & emerging biological applications for multicolor genetic labeling & analysis. Genetics, 2015 Feb; 199(2):293-306. Cover issue. 
  • *Hamling KR, *Tobias ZJC, Weissman TA.  Mapping the development of cerebellar Purkinje cells in zebrafish. Developmental Neurobiology, 2015 Feb 4 doi: 10.1002/dneu.22275 
  • Pan YA, Freundlich T, Weissman TA, Schoppik D, Wang CX, Ciruna B, Sanes JR, Lichtman JW, Schier AF. Zebrabow: multispectral cell labeling for cell tracing and lineage analysis in zebrafish.  Development, 2013 July;140(13):2835-46. 
  • Weissman TA, Sanes JR, Lichtman JW, Livet J. Generating and Imaging Multicolor Brainbow Mice. Cold Spring Harbor Protocols, July 2011 (7:763-9).
  • Livet J, Weissman TA, Kang H, Draft, RW, Lu, J, Bennis RA, Sanes JR, Lichtman JW. Transgenic strategies for combinatorial expression of fluorescent proteins in the nervous system. Nature, Nov 1, 2007, 450 (7166):56-62.
  • Unni VK, Weissman TA, Rockenstein E, Masliah E, McLean PJ, Hyman BT. In vivo imaging of a-synuclein in mouse cortex demonstrates stable expression and differential subcellular compartment mobility. PLoS ONE, May 2010, 5(5):e10589.
  • Weissman T, Ivic L, Riquelme, PA, Flint AC, & Kriegstein AR. Calcium waves propagate through radial glial cells and modulate proliferation in developing cortex. Neuron, September 2, 2004, 43(5):647-661.
  • Weissman T*, Noctor SC*, Clinton BK, Honig LS, & Kriegstein AR. Neurogenic radial glial cells in reptile, rodent, and human: from mitosis to migration. Cerebral Cortex, June 2003, 13(6):550-9.
  • Labrakakis C, Tong C-K, Weissman T, Torsney C, and MacDermott AB. Localization and function of ATP and GABAA receptors expressed by nociceptors and other postnatal rat sensory neurons. Journal of Physiology, May 15, 2003, 549(Pt 1):131-42.
  • Noctor SC, Flint AC, Weissman TA, Wong WS, Clinton BK, & Kriegstein AR. Dividing precursor cells of the embryonic cortical ventricular zone have morphological and molecular characteristics of radial glia. Journal of Neuroscience, April 15, 2002, 22(8):3161-3173.
  • Noctor SC, Flint AC, Weissman TA, Dammerman RS, & Kriegstein AR. Neurons derived from radial glial cells establish radial units in neocortex. Nature, February 8, 2001, 409:714-720.
  • Angelastro JM, Klimaschewski L, Tang, S, Vitolo OV, Weissman TA, Donlin LT, Shelanski ML, & Greene LA. Identification of diverse nerve growth factor-regulated genes by Serial Analysis of Gene profiling. PNAS, September 12, 2000, 97: 10424–10429.
  • Naeser M, Baker E, Palumbo C, Nicholas M, Alexander M, Samaraweera R, M. Prete M, Hodge S, & Weissman T. Lesion site patterns in severe nonverbal aphasia to predict outcome with a computer- assisted treatment program. Archives of Neurology, November, 1998, 55(11):1438-48.

Academic Credentials

PhD Columbia University 2004, BA Pomona College 1992

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Biochemistry and Molecular Biology


Tamily Weissman-Unni’s office is located in room 222 of Biology-Psychology.


voice 503-768-7994

Tamily Weissman-Unni Associate Professor of Biology

Biology Lewis & Clark 0615 S.W. Palatine Hill Road MSC 53 Portland OR 97219 USA

45.451776682575; -122.668801310806