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Recording Light-evoked Postsynaptic Responses in Neurons in Dark-adapted, Mouse Retinal Slice Preparations Using Patch Clamp Techniques
Published on: February 11, 2015
Regulation of ON bipolar cell activity
Josefin Snellman1, Tejinder Kaur, Yin Shen
1Department of Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, SHM-B103, New Haven, CT 06520, USA.
Progress in Retinal and Eye Research
|June 6, 2008
Summary
The mGluR6 receptor in ON bipolar cells is key for retinal signal processing. This review explores how calcium (Ca2+) and cyclic GMP (cGMP) modulate gain at this crucial photoreceptor synapse.
Area of Science:
- Neuroscience
- Retinal Physiology
- Synaptic Transmission
Background:
- The metabotropic glutamate receptor 6 (mGluR6) mediates synaptic transmission from photoreceptors to ON bipolar cells.
- This receptor's unique expression and negative coupling to cation channels create a sign reversal essential for retinal ON/OFF pathways.
Purpose of the Study:
- To review the modulatory roles of Ca2+ and cGMP on synaptic gain at the photoreceptor/ON bipolar cell synapse.
- To examine the sites of action for these second messengers within the mGluR6 signaling cascade.
- To discuss the implications of synaptic plasticity at this site for overall retinal function.
Main Methods:
- Literature review focusing on second messenger modulation of mGluR6 signaling.
- Analysis of studies investigating Ca2+ and cGMP effects on synaptic transmission.
- Synthesis of current knowledge on gain control mechanisms.
Main Results:
- Ca2+ and cGMP act as critical modulators of synaptic gain at the photoreceptor/ON bipolar cell synapse.
- These second messengers influence the mGluR6 cascade on timescales from milliseconds to minutes.
- Specific sites of action within the signaling pathway are proposed for Ca2+ and cGMP.
Conclusions:
- Modulation of gain by Ca2+ and cGMP is vital for adapting retinal signaling.
- Understanding these mechanisms provides insight into retinal processing and potential therapeutic targets.
- Synaptic plasticity at this synapse contributes to the dynamic nature of retinal function.
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