Final answer:
In response to a stimulus, a neuron releases neurotransmitters via exocytosis, which then bind to ligand-gated channels on a neighboring neuron, inducing synaptic signaling.
Step-by-step explanation:
When a neuron is excited by a stimulus, it makes this specific class of hydrophilic ligands known as neurotransmitters. These ligands are transported out of neuron #1 via exocytosis, bind surface receptors, and enter neuron #2 via ligand-gated channel. This is an example of synaptic signaling.
Neurotransmitters are chemical messengers that are crucial for transmitting signals across a synapse from one neuron to another. When an action potential reaches the synaptic terminal of a neuron, it prompts vesicles containing neurotransmitters to fuse with the plasma membrane and release their contents into the synaptic cleft. This type of transport is known as exocytosis and is a form of active transport.
The neurotransmitters then travel across the synaptic cleft and bind to receptors on the surface of the adjacent neuron. Specifically, they bind to ion channel-linked receptors, also known as ionotropic receptors or ligand-gated channels, that are embedded in the neuron’s membrane. Upon binding to these receptors, a conformational change occurs that allows ions to pass through the channel. The influx of ions into neuron #2 alters its membrane potential, leading to depolarization of the membrane, which can eventually trigger an action potential if the threshold is reached.
This entire process represents synaptic signaling, a fundamental aspect of neural communication that underlies all nervous system functions from basic reflex arcs to complex patterns of thought and behavior. Through the precise release and binding of neurotransmitters, neurons can communicate quickly and effectively, enabling the complex operations of the brain and nervous system.