Simulation analysis of receptive-field size of retinal horizontal cells by ionic current model.
The size of the receptive field of retinal horizontal cells changes with the state of dark/light adaptation. We have used a mathematical model to determine how changes in the membrane conductance affect the receptive-field properties of horizontal cells. We first modeled the nonlinear membrane properties of horizontal cells based on ionic current mechanisms. The dissociated horizontal cell model reproduced the voltage-current (V-I) relationships for various extracellular glutamate concentrations measured in electrophysiological studies. Second, a network horizontal cell model was also described, and it reproduced the V-I relationship observed in vivo. The network model showed a bell-shaped relationship between the receptive-field size and constant glutamate concentration. The simulated results suggest that the calcium current is a candidate for the bell-shaped length constant relationship.
Aoyama
Toshihiro
T
Department of Electronic and Information Engineering, Suzuka National College of Technology, Shiroko, Suzuka-City, Japan. aoyama@info.suzuka-ct.ac.jp
Kamiyama
Yoshimi
Y
Usui
Shiro
S
D000818:Animals; D004594:Electrophysiology; D018698:Glutamic Acid / Q000494:pharmacology; D006054:Goldfish; D007473:Ion Channels / Q000502:physiology*; D008564:Membrane Potentials / Q000502:physiology; D008962:Models, Theoretical; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D012160:Retina / Q000187:drug effects / Q000502:physiology*; D014794:Visual Fields / Q000502:physiology*
D007473:Ion Channels; D018698:Glutamic Acid