2001) Temporal contrast adaptation in salamander bipolar cells
Solitary bipolar cells
were prepared from skate retina according to the published protocol (3), and were approved by the IACUCs of the University of Illinois College of Medicine and the Marine Biological Laboratory, Woods Hole, Massachusetts.
In examining controls and exposed mice at postnatal day 60, the researchers found that late-born rod photoreceptors and rod and cone bipolar cells
increased by 16-30% in exposed offspring, whereas Muller glial cells (also classified as late-born retinal cells) did not increase.
By examining specially stained retinal samples under the microscope, they observed structural changes in bipolar cells
in cattle that had been infected with a TSE.
The researchers needed a simple molecule that could make ganglion and bipolar cells
sensitive to light.
In this proposal I wish to examine whether absence of functional miRNAs have as severe implications for the bipolar cells
as they do for cone photoreceptors.
The secondary cells are called ON bipolar cells
because they respond to brightening light, as when lights are turned on.
The molecular mechanisms by which horizontal cells send lateral inhibitory signals to photoreceptors and bipolar cells
are still under debate, but protons released from horizontal cells have been hypothesized to alter the flow of visual information within the outer retina (2).
These minute power surges must leap across tiny gaps, or synapses, to trigger similar potentials in bipolar cells
and ganglion cells that reside in neighboring retinal layers.
Horizontal cells of the vertebrate retina are interneurons; they form a lateral inhibitory pathway in the visual system mediating interactions between photoreceptors and bipolar cells
at the first stage of signal transduction.
Multipolar nerve cells account for 55%, bipolar cells
for 42% and unipolar cells for 2% of the neurons in Hydra (Tardent and Weber, 1976).