Related Experiment Video
Updated: Jan 1, 2026
10:10
Analyzing the Size, Shape, and Directionality of Networks of Coupled Astrocytes
Published on: October 4, 2018
9.3K
Astrocytes Amplify Neuronal Dendritic Volume Transmission Stimulated by Norepinephrine.
Chun Chen1, ZhiYing Jiang1, Xin Fu2
1Department of Cell and Molecular Biology, Tulane University, New Orleans, LA 70118, USA.
Cell Reports
|December 26, 2019
Summary
Norepinephrine activates a novel retrograde signaling pathway involving astrocytes in hypothalamic corticotropin-releasing hormone (CRH) neurons. This mechanism extends dendritic volume transmission to activate upstream neurons, amplifying synaptic circuit activity.
Area of Science:
- Neuroscience
- Cellular Signaling
- Synaptic Plasticity
Background:
- Astrocytes play crucial roles in supporting neuronal function and regulating neurotransmission.
- Bidirectional signaling between neurons and astrocytes is essential for synaptic regulation.
Purpose of the Study:
- To elucidate a novel neuronal-astrocytic signaling pathway.
- To investigate the role of astrocytes in transmitting retrograde dendritic signals to upstream neurons.
- To understand how this pathway activates recurrent synaptic circuits.
Main Methods:
- Utilized a combination of electrophysiology and calcium imaging in hypothalamic corticotropin-releasing hormone (CRH) neurons.
- Investigated the effects of norepinephrine on dendritic release and astrocytic responses.
- Examined the impact of astrocytic ATP release on upstream glutamate and GABA neurons.
Main Results:
- Norepinephrine activates α1 adrenoreceptors on CRH neurons, stimulating dendritic release.
- This release triggers astrocytic calcium responses and subsequent ATP release.
- Astrocytic ATP stimulates action potentials in upstream glutamate and GABA neurons, activating recurrent circuits.
Conclusions:
- A novel retrograde signaling mechanism mediated by astrocytes is identified in CRH neurons.
- This pathway extends dendritic volume transmission to distal presynaptic neurons.
- Norepinephrine amplifies recurrent synaptic circuit activity through this astrocytic engagement.
Related Concept Videos
02:47The Synapse
132.3K
Neurons communicate with one another by passing on their electrical signals to other neurons. A synapse is the location where two neurons meet to exchange signals. At the synapse, the neuron that sends the signal is called the presynaptic cell, while the neuron that receives the message is called the postsynaptic cell. Note that most neurons can be both presynaptic and postsynaptic, as they both transmit and receive information.
132.3K
01:28Neuronal Communication
2.8K
Neurons, the fundamental units of the brain and nervous system, communicate through complex electrochemical signals that underpin all cognitive and bodily functions. This communication is primarily facilitated by a process involving the generation and propagation of an action potential along the axon of the neuron. When the internal electrical charge of a neuron surpasses a certain threshold, an action potential is triggered. This rapid change in voltage travels swiftly along the axon to the...
2.8K
01:27Adrenergic Neurons: Neurotransmission
5.0K
Postganglionic sympathetic fibers (except those supplying the sweat glands) releasing noradrenaline or norepinephrine are called noradrenergic or adrenergic neurons. Noradrenaline, dopamine, adrenaline, or epinephrine are collectively called "catecholamines" as they contain a catechol moiety and an amine side chain. The five stages of neurotransmitter release involve their synthesis, storage, release, reuptake and metabolism.
Synthesis: Catecholamine synthesis requires tyrosine, which...
Synthesis: Catecholamine synthesis requires tyrosine, which...
5.0K
01:12Synaptic Signaling
78.9K
Neurons communicate at synapses, or junctions, to excite or inhibit the activity of other neurons or target cells, such as muscles. Synapses may be chemical or electrical.
78.9K
01:09Synaptic Signaling
6.4K
Neurons communicate at synapses, or junctions, to excite or inhibit the activity of other neurons or target cells, such as muscles. Synapses may be chemical or electrical.
Most synapses are chemical, meaning an electrical impulse or action potential spurs the release of chemical messengers called neurotransmitters. The neuron sending the signal is called the presynaptic neuron, and the neuron receiving the signal is the postsynaptic neuron.
The presynaptic neuron fires an action potential that...
Most synapses are chemical, meaning an electrical impulse or action potential spurs the release of chemical messengers called neurotransmitters. The neuron sending the signal is called the presynaptic neuron, and the neuron receiving the signal is the postsynaptic neuron.
The presynaptic neuron fires an action potential that...
6.4K
01:29Excitatory and Inhibitory Effects of Neurotransmitters
12.4K
When an action potential reaches the presynaptic axon terminal, it releases neurotransmitters from the neuron into the synaptic cleft at a chemical synapse. The released neurotransmitter can be excitatory or inhibitory. The critical criteria commonly used to determine whether a molecule is a neurotransmitter at a chemical synapse are the molecule's presence in the presynaptic neuron. Second, its release is in response to strong presynaptic depolarization. And lastly, the presence of...
12.4K