Regions(s): Neurogenetics; Brain and Behavior; Systems Neuroscience; Cellular and Molecular Neuroscience
Research interest(s): Visual Neuroscience; Neurophysiology; Neuroanatomy; Mouse Genetics; Behavior
Light is an important and ever present regulator of physiology and behavior, and is involved in processes as wide ranging as daily hormonal oscillations, pattern vision, sleep, attention, and circadian photoentrainment. But how are light signals relayed to the brain to mediate these complex visual behaviors? In mammals, all light information reaches the brain via projections from the retinal ganglion cells (RGCs), of which there are ~20 subtypes in the retina. Therefore, to understand how light regulates behavior, we must understand: 1) How do RGC subtypes respond to different light stimuli? 2) What are the specific cellular targets of individual RGC subtypes in the brain? and 3) What are the functional contributions of RGC subtypes to defined visual behaviors?
We study these questions by looking at the role of RGC subtypes in specific visual functions. For example, the intrinsically photosensitive retinal ganglion cells (ipRGCs), which express the photopigment melanopsin, comprise five subtypes that drive a wide range of behaviors from circadian photoentrainment to contrast sensitivity for vision. The defined and quantitative behaviors in which these cells are involved, and the myriad available genetic tools for study of this system make it an ideal one in which to study the circuitry and role of ganglion cells in visual behavior. We do this using a range of techniques from electrophysiology, neuroanatomy, and behavioral approaches in various genetic mouse models.
- Sonoda T and Schmidt TM. (In Press). Reevaluating the role of intrinsically photosensitive retinal ganglion cells: New roles in image forming functions. Integrative and Comparative Biology.
- Schmidt TM, Alam NM, Chen S, Kofuji P, Li W, Prusky GT, Hattar S. (2014). Role for melanopsin in alpha retinal ganglion cells and contrast detection. Neuron, 82(4): 781-788.
- Chew KS, Schmidt TM, Rupp AC, Tremarchi JM. (2014). Loss of Gq/11 genes does not abolish melanopsin phototransduction. PLoSOne, 28;9(5): e98356.
- Sand AM, Schmidt TM, Kofuji P. (2012). Diverse types of ganglion cell photoreceptors in the mammalian retina. Progress in Retinal and Eye Research, 31(4): 287-302.
- Schmidt TM and Kofuji P. (2011). Structure and function of bistratified intrinsically photosensitive retinal ganglion cells in the mouse. J Comp Neurol, 519(8): 1492-1504.
- Schmidt TM, Chen S-K, Hattar S. (2011). Intrinsically photosensitive retinal ganglion cells: many subtypes, diverse functions. Trends Neurosci, 34 (11): 572-580.
- Perez-Leighton CE*, Schmidt TM*, Abramovitz J, Birnbaumer L, Kofuji P. (2011). Intrinsic phototransduction persists in melanopsin-expressing ganglion cells lacking diacylglycerol-sensitive TRPC channel subunits. Euro J Neurosci, 33(5):856-867.
- Schmidt TM and Kofuji P. (2011). An isolated retinal preparation to record light responses from genetically labeled retinal ganglion cells. J Vis Exp, 47.
- Schmidt TM, Do MT, Dacey DM, Lucas R, Hattar S, Matynia A. (2011). Melanopsin-positive intrinsically photosensitive retinal ganglion cells: from form to function. J Neurosci, 31(45): 16094-101.
- Schmidt TM and Kofuji P. (2010). Differential cone pathway influence on intrinsically photosensitive retinal ganglion cell subtypes. J Neurosci, 30 (48): 16262-16271.
- Tang X, Schmidt TM, Perez-Leighton CE, Kofuji P. (2010). Inwardly rectifying potassium channel Kir4.1 is responsible for the native inward potassium conductance of satellite glia cells in sensory ganglia. Neuroscience, 166(2): 397-407.
- Schmidt TM and Kofuji P. (2009). Functional and morphological differences among intrinsically photosensitive retinal ganglion cells. J Neurosci, 29(2): 476-482.
- Schmidt TM. (2009). Role of melastatin-related transient receptor potential channel TRPM1 in the retina: clues taken from horses and mice. J Neurosci, 29(38): 11720-11722.
- Bishop DI, Meyer BC, Schmidt TM, and Gray BR. (2009). Differential investment behavior between grandparents and grandchildren: the role of paternity uncertainty. Evol Psychol, 7(1): 66-77.
- Schmidt TM, Taniguchi K, and Kofuji P. (2008). Intrinsic and extrinsic light responses in melanopsin-expressing ganglion cells during mouse development. J Neurophysiol, 100:371-384.
- Schmidt TM and Kofuji P. (2008). Novel insights into non-image forming visual processing in the retina. Cellscience. 5(1): 77-83.
- 2016 NIH Director’s New Innovator Award
- 2016 Klingenstein-Simons Fellowship in the Neurosciences
- 2016 Karl Kirchgessner Foundation Vision Research Grant
- 2014 Searle Leadership Fund Award, Northwestern University
- 2010 American Legion Brain Sciences Scholarship
- 2010 Milne and Brandenburg Research Award, University of Minnesota
- 2007 Morris Smithberg Memorial Prize, Graduate Program in Neuroscience, University of Minnesota
- 2006 Summa Cum Laude, Luther College
- 2006 Phi Beta Kappa