Forms of intracellular signalling: Synaptic
Synaptic signaling is a form of cell signaling that occurs between neurons, where a neurotransmitter molecule is released by a presynaptic neuron and binds to a receptor on a postsynaptic neuron. In humans, synaptic signaling is involved in many physiological processes, including learning, memory, and sensory perception. Some examples of synaptic signaling pathways in humans include:
- Glutamate signaling: Glutamate is the most abundant excitatory neurotransmitter in the brain and plays a critical role in synaptic plasticity, learning, and memory. Glutamate is released by presynaptic neurons and binds to glutamate receptors on postsynaptic neurons, leading to the activation of downstream signaling pathways that regulate neuronal function.
- GABA signaling: Gamma-aminobutyric acid (GABA) is the most abundant inhibitory neurotransmitter in the brain and plays a critical role in regulating neuronal excitability. GABA is released by presynaptic neurons and binds to GABA receptors on postsynaptic neurons, leading to the activation of downstream signaling pathways that regulate neuronal function.
- Dopamine signaling: Dopamine is a neurotransmitter that plays a critical role in reward, motivation, and movement. Dopamine is released by presynaptic neurons and binds to dopamine receptors on postsynaptic neurons, leading to the activation of downstream signaling pathways that regulate neuronal function.
- Acetylcholine signaling: Acetylcholine is a neurotransmitter that plays a critical role in learning, memory, and muscle function. Acetylcholine is released by presynaptic neurons and binds to acetylcholine receptors on postsynaptic neurons or muscle cells, leading to the activation of downstream signaling pathways that regulate neuronal or muscular function.
Overall, synaptic signaling is a critical mechanism for regulating neuronal function and coordinating communication between neurons in the human brain. Dysregulation of synaptic signaling can contribute to the development of a wide range of neurological and psychiatric disorders, including Alzheimer’s disease, Parkinson’s disease, and schizophrenia. Understanding the mechanisms of synaptic signaling is an important area of research for developing new therapies for these diseases.
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