My laboratory works on the physiology and biophysics of photoreceptors, the retinal cells that convert light energy into electrochemical signals. By studying the properties of rod and cone cells one can understand how the responses of these nerve cells shape and influence human visual behavior. We use isolated retinal tissue from normal and diseased animals to directly measure the electronic response of photoreceptors to light.
Transgenic animal models of retinal degeneration provide an opportunity to investigate precisely how photoreceptor response properties are altered in physiologically challenging environments. By studying diseased tissues we hope to gain new understanding of normal phototransduction mechanisms as well as learn about the progressive loss of photoreceptor signaling ability in retinal diseases.
Other experiments are aimed at developing novel therapies; these may involve the insertion of new genes targeted specifically at the rod photoreceptors. We are exploring the differences between rod and cone phototransduction and are seeking to identify the key molecular components that determine the electrical response properties.
Publications – Recent publications from PubMed
McKeown, AS, Kraft, TW, & MS Loop (2015). Increased visual sensitivity following periods of dim illumination. Invest Ophthalmol Vis Sci 56:1864-1871; published February 19, 2015, doi:10.1167/iovs.14-15958
Sarfare, S.S., McKeown, A.S., Messinger, J.D., Wei, H-J., Rubin, G.S., Kraft, T.W., & S.J. Pittler. (2014) Overexpression of rod photoreceptor glutamic acid rich protein 2 (GARP2) increases gain and slows recovery in mouse retina. Cell and Communication Signaling. 12(1):67
F Crittenden, H Thomas, CM Ethen, ZL Wu, D Chen, TW Kraft, J Parant, CN Falany (2014) Inhibition of SULT4A1 Expression Induces Up-regulation of Phototransduction Gene Expression in 72 Hours Post Fertilization Zebrafish Larvae. Drug Metab Dispos dmd.114.057042; epub Feb 19, 2014, doi:10.1124/dmd.114.057042
McKeown, AS and Kraft, TW (2014) Adaptive potentiation in rod photoreceptors. J. Gen. Physiol. 143 (6), 733-743. PMID: 24821966
Ward, ME, Taubes, A, Miller, BL, Chen, R, Sephton, CF, Gelfand, JM, Boscardin, J, Martens, LH, Seeley, WW, Yu, G, Herz, J, Filiano, A, Roberson, E, Kraft, TW, Farese, RV Jr, Green, A, Gan, L (2014) Early retinal neurodegeneration and impaired Ran-mediated nuclear import of TDP-43 in progranulin-deficient FTLF. J Exp Med 211:1937-1945.
Berbari, NF, Malarkey, EB, Zaki, SM, Yazdi, ZR, McNair, AD, Croyle, MJ, Kraft, TW, Yoder, BK (2014) Hippocampal and cortical primary cilia are required aversive memory in mice (ePub Sep 3, 2014) Plos One 9 (9) e106576
Reish, NJ, Maltare, A, McKeown, AS Laszczyk, AM, Kraft, TW, Gross, AK, & GD King (2013) The age-regulating protein klotho is vital to sustained retinal function. Invest Ophthalmol Vis Sci.54:6675–6685. DOI:10.1167 iovs.13-12550 PMID: 24045987
1 rhodopsin mutatations in congenital night blindness (2010). McAlear SD, Kraft TW, Gross AK. Adv Exp Med Biol. 664:263-72.PMID: 20238025
Moayed, AA, Hariri, S, Hyun, C, Doran, B, Kraft, TW, Boyd, S. and K Bizheva (2010). Combined optical coherence tomography and electroretinography system for in vivo simultaneous morphological and functional imaging of the rodent retina. J. Biomed. Opt 15(4): 040506. PMID: 20799773
Zhang, Y Molday, L.L., Molday, R.S. Woodruff M., Fain GL, Kraft, T.W., and. Pittler, S.J., (2009) Knockout of cGMP-gated channel &[beta]-subunit and GARPs disrupts disk morphogenesis and rod outer segment structural integrity. J Cell Sci. Jun 1;122(Pt 11):1927. PMID: 19339551
Hancock, H.A., & Kraft T.W. (2008). Human Oscillatory Potential: Intensity Dependence of Timing and Amplitude E-pub 04.30.08, Documenta Ophthalmologica. 117 (3): 215-222.
Rubin, G. R., & Kraft, T. W. (2007). Flicker assessment of rod and cone function in a model of retinal degeneration. E-pub 08.03.07, Documenta Ophthalmologica.115: 165-172.
Kraft, T. W., Allen, D., Petters, R., Hao, Y., Peng, Y.-W., and Wong, F. (2005) Altered light responses of single rod photoreceptors in transgenic pigs expressing P347L or P347S rhodopsin. Molecular Vision 11:1246-1256.
L.M. Brockway, D.J. Benos, K.T. Keyser, and T.W. Kraft (2005) Blockade of amiloride-sensitive sodium channels alters multiple components of the mammalian electroretinogram. Visual Neuroscience vol 22: 2) 143-151.
Hancock, H. A., Ready, E. L., Guidry, C., Read, R. W. and Kraft, T. W. (2005) Acute aminoglycoside retinal toxicity in vivo and in vitro. Investigative Ophthalmology and Visual Science. 46 (12): 4804-8.
Hancock, H. A., and Kraft, T. W. (2004). Oscillatory potentials analysis and ERGs of normal and diabetic rats. Investigative Ophthalmology and Visual Science. 45(3) 1002-1008.
Zhang X., Wensel T. G., Kraft T. W. (2003) GTPase Regulators and Photoresponses in Cones of the Eastern Chipmunk. J. Neurosci. 23(4) 1287-1297.
Savtchenko, A., Kraft, T. W., Molokanova, E. and Kramer, R. H., (2001) Growth factors regulate phototransduction by modulating cyclic nucleotide-gated channels through dephosphorylation of a specific tyrosine residue Proceeding of the National Academy of Sciences, USA 98(10):5880-5885.
B.S., Life Sciences, Massachusetts Institute of Technology
Ph.D., Physiology, University of Minnesota
Postdoctoral Scholar Stanford University, Department of Neurobiology
Postdoctoral Scholar University of California at San Francisco, Ophthalmology