Related Experiment Video
Updated: Sep 3, 2025
11:39
Simultaneous Whole-cell Recordings from Photoreceptors and Second-order Neurons in an Amphibian Retinal Slice Preparation
Published on: June 1, 2013
13.8K
Multiple Calcium Channel Types with Unique Expression Patterns Mediate Retinal Signaling at Bipolar Cell Ribbon
Gong Zhang1, Jun-Bin Liu1, He-Lan Yuan1
1State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou 510060, China.
Summary
This study reveals that retinal bipolar cell synapses utilize a diverse array of voltage-gated calcium (Ca 2+ ) channels, including P/Q-type and N-type, not just L-type. This finding broadens our understanding of synaptic transmission in the retina.
Area of Science:
- Neuroscience
- Cell Biology
- Molecular Biology
Background:
- Retinal bipolar cells (BCs) are crucial for transmitting visual information from photoreceptors.
- Synaptic transmission in BCs was previously thought to rely primarily on L-type voltage-gated calcium (Ca 2+ ) channels.
Purpose of the Study:
- To investigate the molecular identity and expression profiles of Ca 2+ channel subunits in mouse rod bipolar (RB) cells.
- To determine the types of Ca 2+ conductances mediating synaptic transmission in RB cells.
Main Methods:
- Combined molecular and functional analyses of Ca 2+ channel (Ca V ) α 1 , β, and α 2 δ subunits in mouse RB cells.
- Analysis of Ca 2+ influx through various Ca 2+ channel subtypes in RB cell synapses.
Main Results:
- Significant heterogeneity in Ca 2+ channel subunit expression was observed in RB cells.
- Synaptic transmission from RB cell synapses is mediated by P/Q-type (Ca V 2.1), N-type (Ca V 2.2), L-type (Ca V 1), and T-type (Ca V 3) conductances.
- Ca V 1.3 and Ca V 1.4 proteins were localized to presynaptic active zones in RB axon terminals.
- Ca 2+ channel subunits (Ca V 1, Ca V 3, β, and α 2 δ) exhibited a 'multisubtype' expression rule, with multiple subtypes present in individual cells.
Conclusions:
- The molecular identity of Ca 2+ channels in retinal bipolar cells is more diverse than previously assumed.
- Synaptic transmission in RB cells involves a combination of multiple Ca 2+ channel subtypes, challenging the long-held view of L-type channel exclusivity.
Related Concept Videos
01:32The Retina
69.8K
The retina is a layer of nervous tissue at the back of the eye that transduces light into neural signals. This process, called phototransduction, is carried out by rod and cone photoreceptor cells in the back of the retina.
69.8K
01:21G-Protein Gated Ion Channels
4.8K
GPCRs are primarily responsible for our sense of smell, taste, and vision. The binding of a sensory stimulus activates GPCR to stimulate effector proteins, many of which are ion channels in the sensory organs. GPCRs modulate the opening and closing of the target ion channels either directly by binding them, or by releasing second messengers that activate these channels. As ions move across the membrane, the membrane potential is altered, which induces an appropriate response.
Sensory...
Sensory...
4.8K
01:11Channel Rhodopsins
2.6K
Most organisms use photoreceptors to sense and respond to light. Examples of photoreceptors include bacteriorhodopsins and bacteriophytochromes in some bacteria, phytochromes in plants, and rhodopsins in the photoreceptor cells of the vertebral retina. The light-sensitive property of these receptors is because of the bound chromophores, such as bilin in the phytochromes and retinal in the rhodopsins.
Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,...
Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,...
2.6K
01:22Photoreceptors and Visual Pathways
6.4K
At the molecular level, visual signals trigger transformations in photopigment molecules, resulting in changes in the photoreceptor cell's membrane potential. The photon's energy level is denoted by its wavelength, with each specific wavelength of visible light associated with a distinct color. The spectral range of visible light, classified as electromagnetic radiation, spans from 380 to 720 nm. Electromagnetic radiation wavelengths exceeding 720 nm fall under the infrared category,...
6.4K
01:26Chemical Synapses
9.1K
Chemical synapses are specialized sites between two neurons or between a neuron and a non-neuronal cell like a muscle, glandular or sensory cell.
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
Because chemical synapses depend on the release of neurotransmitter molecules from synaptic vesicles to pass on their signal, there is an approximately one millisecond delay between when the axon potential reaches the presynaptic terminal and when the neurotransmitter leads to opening of postsynaptic ion channels. Additionally, this signaling is...
9.1K
01:20Anatomy of the Eyeball
7.5K
The eye is a spherical, hollow structure composed of three tissue layers. The outer layer — the fibrous tunic, comprises the sclera — a white structure — and the cornea, which is transparent. The sclera encompasses some of the ocular surface, most of which is not visible. However, the 'white of the eye' is distinctively visible in humans compared to other species. The cornea, a clear covering at the front of the eye, enables light penetration. The eye's middle...
7.5K