Neurons of the vertebrate retina will be studied in a preparation of isolated cells maintained in cell culture. The overall goal of the project is to determine how the individual neurons of the vertebrate retina process visual information. The techniques of whole-cell and single-channel voltage-clamp will be used to characterize the voltage and neurotransmitter gated ionic currents intrinsic to the membranes of retinal horizontal, bipolar and ganglion cells. Specifically, the neurons will be voltage- clamped and potassium and calcium currents investigated. I-V characteristics will be studied as well as gating, kinetics of currents, activation and inactivation. Single channel recordings will be carried out to investigate the properties of retinal potassium and calcium channels and to make comparisons with those types of channels found in the CNS. Putative photoreceptor neurotransmitters such as glutamate, kainate and quisqualate will be studied in an effort to determine how these transmitters modulate the membrane properties of horizontal and bipolar cells. For similar reasons, the actions of putative amacrine cell transmitters on ganglion cells will be studied. The modulation of electrical coupling between horizontal cells will also be investigated using these techniques. The use of isolated retinal neurons is a powerful tool which allows the study of the physiology of retinal cells outside of the retinal network. Problems such as the state of light adaptation and indirect effects of neurotransmitters due to a multiplicity of inputs are not present. As a result, information can be gathered which was previously inaccessible. This project will provide knowledge about the basic properties of ionic channels in retinal cell membranes and how these channels are modulated to influence the signalling capabilities of the cell. This will lead to a better comprehension of how retinal neurons operate, as well as an increased understanding of how the nervous system in general processes information.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY005972-09
Application #
2159682
Study Section
Visual Sciences A Study Section (VISA)
Project Start
1985-08-01
Project End
1995-03-31
Budget Start
1994-04-01
Budget End
1995-03-31
Support Year
9
Fiscal Year
1994
Total Cost
Indirect Cost
Name
University of Utah
Department
Physiology
Type
Schools of Medicine
DUNS #
City
Salt Lake City
State
UT
Country
United States
Zip Code
84112
Solessio, E; Rapp, K; Perlman, I et al. (2001) Spermine mediates inward rectification in potassium channels of turtle retinal Muller cells. J Neurophysiol 85:1357-67
Solessio, E; Linn, D M; Perlman, I et al. (2000) Characterization with barium of potassium currents in turtle retinal Muller cells. J Neurophysiol 83:418-30
Linn, D M; Solessio, E; Perlman, I et al. (1998) The role of potassium conductance in the generation of light responses in Muller cells of the turtle retina. Vis Neurosci 15:449-58
Liu, Y; Lasater, E M (1994) Calcium currents in turtle retinal ganglion cells. I. The properties of T- and L-type currents. J Neurophysiol 71:733-42
Liu, Y; Lasater, E M (1994) Calcium currents in turtle retinal ganglion cells. II. Dopamine modulation via a cyclic AMP-dependent mechanism. J Neurophysiol 71:743-52
Perlman, I; Sullivan, J M; Normann, R A (1993) Voltage- and time-dependent potassium conductances enhance the frequency response of horizontal cells in the turtle retina. Brain Res 619:89-97
Pfeiffer-Linn, C; Lasater, E M (1993) Dopamine modulates in a differential fashion T- and L-type calcium currents in bass retinal horizontal cells. J Gen Physiol 102:277-94
Vaughan, D K; Lasater, E M (1992) Acid phosphatase localization in endocytosed horizontal cell gap junctions. Vis Neurosci 8:77-81
Sullivan, J M; Lasater, E M (1992) Sustained and transient calcium currents in horizontal cells of the white bass retina. J Gen Physiol 99:84-107
Lasater, E M (1991) Characteristics of single-channels activated by quisqualate and kainate in teleost retinal horizontal cells. Vision Res 31:413-24

Showing the most recent 10 out of 21 publications