Ralph J Jensen

Summary

Country: USA

Publications

  1. doi request reprint Activation of ganglion cells in wild-type and P23H rat retinas with a small subretinal electrode
    Ralph J Jensen
    VA Boston Healthcare System, Mail Stop 151E, 150 South Huntington Avenue, Boston, MA 02130, USA
    Exp Eye Res 99:71-7. 2012
  2. doi request reprint Blocking GABA(C) receptors increases light responsiveness of retinal ganglion cells in a rat model of retinitis pigmentosa
    Ralph J Jensen
    VA Boston Healthcare System, Mail Stop 151E, 150 South Huntington Avenue, Boston, MA 02130, USA
    Exp Eye Res 105:21-6. 2012
  3. doi request reprint Effects of GABA receptor antagonists on thresholds of P23H rat retinal ganglion cells to electrical stimulation of the retina
    Ralph J Jensen
    The Center for Innovative Visual Rehabilitation, VA Boston Healthcare System, Mail Stop 151E, 150 South Huntington Avenue, Boston, MA 02130, USA
    J Neural Eng 8:035002. 2011
  4. doi request reprint Spatiotemporal aspects of pulsed electrical stimuli on the responses of rabbit retinal ganglion cells
    Ralph J Jensen
    The Center for Innovative Visual Rehabilitation, VA Boston Healthcare System, Mail Stop 151E, 150 South Huntington Avenue, Boston, MA 02130, USA
    Exp Eye Res 89:972-9. 2009
  5. doi request reprint Activation of ganglion cells in wild-type and rd1 mouse retinas with monophasic and biphasic current pulses
    Ralph J Jensen
    The Center for Innovative Visual Rehabilitation, VA Boston Healthcare System, Boston, MA 02130, USA
    J Neural Eng 6:035004. 2009
  6. doi request reprint Activation of retinal ganglion cells in wild-type and rd1 mice through electrical stimulation of the retinal neural network
    Ralph J Jensen
    The Center for Innovative Visual Rehabilitation, VA Boston Healthcare System, 150 South Huntington Avenue, Mail Stop 151E, Boston, MA 02130, USA
    Vision Res 48:1562-8. 2008
  7. ncbi request reprint Responses of ganglion cells to repetitive electrical stimulation of the retina
    Ralph J Jensen
    The Center for Innovative Visual Rehabilitation, VA Boston Healthcare System, Mail Stop 151E, 150 South Huntington Avenue, Boston, MA 02130, USA
    J Neural Eng 4:S1-6. 2007
  8. ncbi request reprint Thresholds for activation of rabbit retinal ganglion cells with a subretinal electrode
    Ralph J Jensen
    Center for Innovative Visual Rehabilitation, VA Boston Healthcare System, 150 South Huntington Avenue, Mail Stop 151E, Boston, MA 02130, USA
    Exp Eye Res 83:367-73. 2006
  9. ncbi request reprint In vitro activation of retinal cells: estimating location of stimulated cell by using a mathematical model
    Ofer R Ziv
    The Center for Innovative Visual Rehabilitation, VA Medical Center, Mail Stop 151E, 150 South Huntington Avenue, Boston, MA 02130, USA
    J Neural Eng 2:S5-S15. 2005
  10. ncbi request reprint Responses of rabbit retinal ganglion cells to electrical stimulation with an epiretinal electrode
    Ralph J Jensen
    The Center for Innovative Visual Rehabilitation, VA Medical Center, Mail Stop 151E, 150 South Huntington Avenue, Boston, MA 02130, USA
    J Neural Eng 2:S16-21. 2005

Detail Information

Publications13

  1. doi request reprint Activation of ganglion cells in wild-type and P23H rat retinas with a small subretinal electrode
    Ralph J Jensen
    VA Boston Healthcare System, Mail Stop 151E, 150 South Huntington Avenue, Boston, MA 02130, USA
    Exp Eye Res 99:71-7. 2012
    ..Our findings indicate that the spread of activation of RGCs is more confined in the degenerate retina. Lastly, my findings indicate that photoreceptors contribute to the lower stimulation thresholds of RGCs in normal, healthy retinas...
  2. doi request reprint Blocking GABA(C) receptors increases light responsiveness of retinal ganglion cells in a rat model of retinitis pigmentosa
    Ralph J Jensen
    VA Boston Healthcare System, Mail Stop 151E, 150 South Huntington Avenue, Boston, MA 02130, USA
    Exp Eye Res 105:21-6. 2012
    ..20 log unit. In conclusion, GABA(C) receptors may be novel targets for therapeutic interventions aimed at increasing light responsiveness in patients with retinitis pigmentosa or other diseases involving degeneration of photoreceptors...
  3. doi request reprint Effects of GABA receptor antagonists on thresholds of P23H rat retinal ganglion cells to electrical stimulation of the retina
    Ralph J Jensen
    The Center for Innovative Visual Rehabilitation, VA Boston Healthcare System, Mail Stop 151E, 150 South Huntington Avenue, Boston, MA 02130, USA
    J Neural Eng 8:035002. 2011
    ..We suggest that the effects of the GABA receptor antagonists on ON-center RGCs may be attributable to blockage of GABA receptors on the axon terminals of ON bipolar cells...
  4. doi request reprint Spatiotemporal aspects of pulsed electrical stimuli on the responses of rabbit retinal ganglion cells
    Ralph J Jensen
    The Center for Innovative Visual Rehabilitation, VA Boston Healthcare System, Mail Stop 151E, 150 South Huntington Avenue, Boston, MA 02130, USA
    Exp Eye Res 89:972-9. 2009
    ..These findings suggest that simple translation of object motion to sequential stimulation through neighboring electrodes may not be the best way to convey the perception of object motion in a patient with a retinal prosthesis...
  5. doi request reprint Activation of ganglion cells in wild-type and rd1 mouse retinas with monophasic and biphasic current pulses
    Ralph J Jensen
    The Center for Innovative Visual Rehabilitation, VA Boston Healthcare System, Boston, MA 02130, USA
    J Neural Eng 6:035004. 2009
    ..Thus, a symmetric biphasic current pulse may be the best stimulus for activating the greatest number of RGCs in retinas devoid of photoreceptors...
  6. doi request reprint Activation of retinal ganglion cells in wild-type and rd1 mice through electrical stimulation of the retinal neural network
    Ralph J Jensen
    The Center for Innovative Visual Rehabilitation, VA Boston Healthcare System, 150 South Huntington Avenue, Mail Stop 151E, Boston, MA 02130, USA
    Vision Res 48:1562-8. 2008
    ..We propose that photoreceptors lower the thresholds for activation of RGCs whereas postreceptoral neurons determine the response properties of RGCs to electrical stimuli...
  7. ncbi request reprint Responses of ganglion cells to repetitive electrical stimulation of the retina
    Ralph J Jensen
    The Center for Innovative Visual Rehabilitation, VA Boston Healthcare System, Mail Stop 151E, 150 South Huntington Avenue, Boston, MA 02130, USA
    J Neural Eng 4:S1-6. 2007
    ..The depression with each successive pulse was relatively moderate compared to the depression to the second pulse. The results of this study have implications for the design of electrical stimulation strategies in a retinal prosthesis...
  8. ncbi request reprint Thresholds for activation of rabbit retinal ganglion cells with a subretinal electrode
    Ralph J Jensen
    Center for Innovative Visual Rehabilitation, VA Boston Healthcare System, 150 South Huntington Avenue, Mail Stop 151E, Boston, MA 02130, USA
    Exp Eye Res 83:367-73. 2006
    ..With respect to a subretinal prosthesis, our findings suggest the possibility that cathodal current pulses may bias activation of ON RGCs in blind patients...
  9. ncbi request reprint In vitro activation of retinal cells: estimating location of stimulated cell by using a mathematical model
    Ofer R Ziv
    The Center for Innovative Visual Rehabilitation, VA Medical Center, Mail Stop 151E, 150 South Huntington Avenue, Boston, MA 02130, USA
    J Neural Eng 2:S5-S15. 2005
    ..Our model would have to be tested with a larger threshold data pool to permit more conclusive statements about the relative value of our model versus the traditional square law model under special circumstances...
  10. ncbi request reprint Responses of rabbit retinal ganglion cells to electrical stimulation with an epiretinal electrode
    Ralph J Jensen
    The Center for Innovative Visual Rehabilitation, VA Medical Center, Mail Stop 151E, 150 South Huntington Avenue, Boston, MA 02130, USA
    J Neural Eng 2:S16-21. 2005
    ..In ON RGCs, the average threshold current was 13 microA for a cathodal stimulus and 15 microA for an anodal stimulus...
  11. ncbi request reprint Thresholds for activation of rabbit retinal ganglion cells with relatively large, extracellular microelectrodes
    Ralph J Jensen
    Center for Innovative Visual Rehabilitation, VA Boston Healthcare System, Boston, Massachusetts, USA
    Invest Ophthalmol Vis Sci 46:1486-96. 2005
    ..To investigate the responses of retinal ganglion cells (RGCs) to electrical stimulation, using electrodes comparable in size to those used in human studies investigating the feasibility of an electronic retinal prosthesis...
  12. ncbi request reprint Thresholds for activation of rabbit retinal ganglion cells with an ultrafine, extracellular microelectrode
    Ralph J Jensen
    Center for Innovative Visual Rehabilitation, VA Medical Center, Boston, Massachusetts, USA
    Invest Ophthalmol Vis Sci 44:3533-43. 2003
    ..To determine electrical thresholds required for extracellular activation of retinal ganglion cells as part of a project to develop an epiretinal prosthesis...
  13. ncbi request reprint Activation of group II metabotropic glutamate receptors reduces directional selectivity in retinal ganglion cells
    Ralph J Jensen
    Center for Innovative Visual Rehabilitation, VA Boston Healthcare System, 150 South Huntington Ave MS 151E, Boston, MA 02130, USA
    Brain Res 1122:86-92. 2006
    ..Overall, the results suggest that postsynaptic group II mGluRs have the potential to influence directional selectivity in RGCs by inhibiting transmitter release from starburst amacrine cells...