Accession Number:

ADA411141

Title:

How Efficiently A Ganglion Cell Codes the Visual Signal

Descriptive Note:

Corporate Author:

PENNSYLVANIA UNIV PHILADELPHIA DEPT OFNEUROSCIENCE

Report Date:

2001-10-25

Pagination or Media Count:

4.0

Abstract:

The retinas visual message is transmitted to the brain by ganglion cells that integrate noisy synaptic inputs to create a spike train. We asked how efficiently the retinal ganglion cell spike generator creates the spike train message. Intracellular and extracellular recordings were made from in vitro guinea pig retina, in response to a spot of light flashed over the receptive field center. Responses were analyzed with an ideal observer, a program that discriminated between two contrasts based on an optimal decision rule. Spike trains from ganglion cells had thresholds as low as 1 contrast, but thresholds for the corresponding graded potentials were lower by a factor of 2. Using a computational model of the ganglion cell, we asked what factors in the spike generator mechanism are responsible for the spike trains loss in performance. The model included dendriticaxonal morphology, noisy synaptic inputs and membrane channels.

Subject Categories:

  • Anatomy and Physiology
  • Medicine and Medical Research

Distribution Statement:

APPROVED FOR PUBLIC RELEASE