Related Experiment Video
Updated: Aug 19, 2026

Immunohistochemical and Calcium Imaging Methods in Wholemount Rat Retina
Published on: October 13, 2014
The resting release of acetylcholine by a retinal neuron
1Department of Physiology, Harvard Medical School, Boston Massachusetts 02115.
Abstract:
The cholinergic amacrine cells of the rabbit retina secrete acetylcholine by two mechanisms. One is activated by stimulation of the retina by light or depolarization of the amacrine cells by K+ ions. It requires the presence of extracellular Ca2+. The second is independent of extracellular Ca2+ and is unaffected by large depolarizations of the cells. It bears some similarity to the acetylcholine 'leakage' described at the neuromuscular junction. Although the Ca2+-independent mechanism accounts for about two thirds of the total acetylcholine release in the dark, the amount of acetylcholine released in this way is small compared with the release of acetylcholine triggered by stimulation of the retina with light. Its biological significance is unclear.
More Related Videos
10:30Recording Light-evoked Postsynaptic Responses in Neurons in Dark-adapted, Mouse Retinal Slice Preparations Using Patch Clamp Techniques
Published on: February 11, 2015
08:44Patch Clamp Recording of Starburst Amacrine Cells in a Flat-mount Preparation of Deafferentated Mouse Retina
Published on: October 13, 2016
Related Concept Videos
Chemical Synapses
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...
Cholinergic Neurons: Neurotransmission
Adrenergic Neurons: Neurotransmission
Synthesis: Catecholamine synthesis requires tyrosine, which is taken...
Relaxation of Skeletal Muscles
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open.
Chemical Synapses
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...
Parasympathetic Signaling
The effects of...