glutamatergic synapse

Definition

Target type: cellularcomponent

A synapse that uses glutamate as a neurotransmitter. [GOC:dos]

The glutamatergic synapse is a specialized junction between neurons where the neurotransmitter glutamate is released from the presynaptic neuron and binds to receptors on the postsynaptic neuron. This interaction triggers a signal that propagates along the postsynaptic neuron, ultimately leading to the transmission of information. The cellular components of a glutamatergic synapse can be broadly categorized into presynaptic, postsynaptic, and perisynaptic elements.

**Presynaptic Components**

* **Presynaptic terminal:** This is the bulb-like swelling at the end of the presynaptic axon. It contains synaptic vesicles filled with glutamate.
* **Active zones:** These are specialized regions within the presynaptic terminal where glutamate is released. They are characterized by a dense protein scaffold that includes proteins like synapsin, RIM, and Munc13.
* **Synaptic vesicles:** These are small membrane-bound sacs that store glutamate. They are loaded with glutamate via specialized transporters and undergo exocytosis, releasing glutamate into the synaptic cleft upon arrival of an action potential.
* **Voltage-gated calcium channels:** These channels open in response to depolarization of the presynaptic terminal, allowing calcium ions to flow into the terminal. Calcium influx triggers the fusion of synaptic vesicles with the presynaptic membrane and the release of glutamate.

**Postsynaptic Components**

* **Postsynaptic density (PSD):** This is a dense protein scaffold on the postsynaptic membrane that acts as a platform for glutamate receptors, signaling molecules, and scaffolding proteins.
* **Glutamate receptors:** These are transmembrane proteins that bind glutamate and initiate postsynaptic signaling. There are several types of glutamate receptors, including AMPA receptors, NMDA receptors, and kainate receptors, each with distinct properties and roles in synaptic transmission.
* **Signaling molecules:** Once glutamate binds to receptors, it triggers a cascade of intracellular signaling events that can lead to changes in neuronal excitability, gene expression, and synaptic plasticity.

**Perisynaptic Components**

* **Astrocytes:** These glial cells surround synapses and play a role in regulating synaptic transmission. They take up glutamate from the synaptic cleft, preventing its accumulation and ensuring proper synaptic function.
* **Microglia:** These immune cells of the brain can engulf and degrade synapses, contributing to synaptic pruning and plasticity.

**Other Components**

* **Synaptic cleft:** This is the narrow gap between the presynaptic and postsynaptic terminals. It is filled with extracellular matrix, which helps to maintain the structure of the synapse and allows for the diffusion of glutamate from the presynaptic terminal to the postsynaptic receptors.

The precise composition and organization of the cellular components of a glutamatergic synapse can vary depending on the specific neuronal type, brain region, and developmental stage. However, the basic principles of glutamate release, receptor activation, and postsynaptic signaling remain consistent across different glutamatergic synapses.'
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Proteins (124)

Compounds (2,706)