Positive Feedback in Retinal Synapses
Author Information
Author(s): Jackman Skyler L., Babai Norbert, Chambers James J., Thoreson Wallace B., Kramer Richard H.
Primary Institution: University of California, Berkeley
Hypothesis
Do horizontal cells provide a positive feedback signal to cone photoreceptors?
Conclusion
Horizontal cells transmit a positive feedback signal to cone photoreceptors, enhancing neurotransmitter release.
Supporting Evidence
- Glutamate application increased vesicular release from cone terminals by approximately 4-fold.
- AMPA receptors on horizontal cells mediate the positive feedback signal.
- Local uncaging of AMPA showed that positive feedback is spatially constrained to active HC-cone synapses.
- Blocking AMPA receptors significantly reduced the release rate from cone terminals.
Takeaway
The study found that cells in the retina can help each other by sending signals that make them work better together, like cheering each other on.
Methodology
The study used fluorescence microscopy to monitor synaptic vesicle release from cone terminals and various pharmacological agents to assess feedback mechanisms.
Limitations
The positive feedback mechanism may be compromised in retinal slices, which are commonly used for electrophysiological recordings.
Statistical Information
P-Value
p<0.001
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
Want to read the original?
Access the complete publication on the publisher's website