Release of Neurotransmitter at the synaptic cleft Part 4 neuronal Signaling

>> YOUR LINK HERE: ___ http://youtube.com/watch?v=3xHRf0jZsso

#biotechnology #neurology #neurotransmitters #neurons #releaseofneurotransmitters #SynapticCleft #neuroscience #neurobiology #chemicalsynapsis #synapsis • This is the 4th part on the neuronal signaling and is focusing on the release of Neurotransmitter at the synaptic cleft. The links to the 1st three parts are given below • Part 1, structure of neuron : • Structure of Neurons, Part 1 neuronal... • Part 2, Types of neurons, • Types of Neurons, Part 2 neuronal Sig... • Part 3: Action potential: • Action Potential; How neurons work an... • At rest, neurotransmitter-containing vesicles are stored at the terminal of the neuron in one of two places. A small number of vesicles are positioned along the pre-synaptic membrane in places called active zones. This is where neurotransmitter release occurs. Most vesicles, however, are held close to these zones, yet further from the membrane itself until they are needed. These vesicles are held in place by Ca2+ sensitive vesicle membrane proteins (VAMPs), which bind to actin filaments, microtubules, and various other elements of the cytoskeleton. • When an action potential reaches the terminal of a presynaptic neuron, voltage-dependent calcium (Ca2+) channels embedded in the pre-synaptic membrane open and Ca2+ rushes in. This influx of calcium ions triggers a series of events, which ultimately results in the release of the neurotransmitter from a storage vesicle into the synaptic cleft. • The release of neurotransmitters at the synaptic cleft is a crucial step in the process of neural communication. When an action potential reaches the presynaptic terminal of a neuron, it travels down the axon of a presynaptic neuron towards the synaptic terminal. As the action potential reaches the synaptic terminal, it causes the opening of voltage-gated calcium channels in the presynaptic membrane. Calcium ions (Ca2+) rush into the terminal due to the concentration gradient. • The influx of calcium ions leads to the fusion of synaptic vesicles containing neurotransmitter molecules with the presynaptic membrane. This fusion is facilitated by proteins called SNARE proteins. Once the synaptic vesicles fuse with the presynaptic membrane, neurotransmitters are released into the synaptic cleft through a process called exocytosis. The neurotransmitters are then free to diffuse across the cleft. • The released neurotransmitters diffuse across the synaptic cleft and bind to specific receptor molecules located on the postsynaptic membrane. These receptors are typically ligand-gated ion channels or G protein-coupled receptors. • Postsynaptic response: • The binding of neurotransmitters to their receptors on the postsynaptic membrane can cause various effects. For example, ligand-gated ion channels can open or close, leading to changes in the postsynaptic membrane potential. G protein-coupled receptors can initiate signaling cascades inside the postsynaptic neuron, influencing its activity. After neurotransmitters have exerted their effect, they are removed from the synaptic cleft to terminate their action. This removal can occur through various mechanisms, including reuptake by the presynaptic neuron, enzymatic degradation, or diffusion away from the synapse. • It's important to note that the process of neurotransmitter release and synaptic communication can be modulated by various factors, including the strength of the incoming signal, the availability of calcium ions, and the functioning of the presynaptic and postsynaptic receptors. These factors contribute to the complex dynamics of neural communication in the brain.

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