On Directional Selectivity in Vertebrate Retina: An Experimental and Computational Study
Abstract
The retina is a good candidate for exploring the relationship between neural computation and circuit, in particular given its physically peripheral location and its physiologically central status. One example of a spatial- temporal computation in the retina is directional selectivity. This computation may rely on interactions within the dendritic tree which are incrementally more complex than the basic 'point integration' and fire neuronal response. In this Thesis I use experimental and theoretical techniques to characterize the direction selectivity circuit in vertebrate retina. For the experimental side I have developed an (1) isolated intact turtle retina preparation and (2) a whole- cell patch recording protocol of directionally selective ganglion cells, the combination of which is well-suited for characterizing complicated retinal receptive fields. I will show evidence that when the inhibitory synaptic input is markedly reduced the excitatory input to directionally selective ganglion cells in turtle is itself directionally selective. This reduction was accomplished (1) by voltage clamping to the reversal potential of inhibitory currents and (2) by removing ATP from the electrodes which, in turn, blocks the inhibitory input over time.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1992
- Accession Number
- ADA259493
Entities
People
- Lyle J. Borg-graham
Organizations
- Massachusetts Institute of Technology