What is an example of an action potential?

Hello, I'm a neuroscience enthusiast with a keen interest in the mechanisms of neural communication. One of the fundamental concepts in this field is the action potential, which is the electrical signal that travels along neurons. An example of an action potential can be described in the following steps: 1. Resting Potential: A neuron at rest has a negative charge inside the cell relative to the outside, typically around -70 millivolts (mV). 2. Stimulus: When a stimulus is applied, it can cause some of the ion channels in the neuron's membrane to open, allowing positively charged ions (sodium ions) to flow into the cell. 3. Depolarization: As sodium ions enter, they make the inside of the cell more positive. If this depolarization reaches a certain threshold (usually around -55 mV), it triggers an action potential. 4. Action Potential Initiation: At the threshold, voltage-gated ion channels open rapidly, causing a large influx of sodium ions, which makes the inside of the cell even more positive, typically reaching around +40 mV. 5. Repolarization: After the peak is reached, the sodium channels close, and potassium channels open, allowing potassium ions to flow out of the cell, which starts to bring the cell's voltage back down toward the resting potential. 6. Hyperpolarization: The potassium channels stay open longer than necessary to just bring the cell back to its resting potential, causing a brief hyperpolarization (a more negative voltage than the resting potential). 7. Return to Resting Potential: The potassium channels close, and the cell returns to its resting state, ready to generate another action potential if stimulated again. This sequence of events is an example of an action potential, which is crucial for the transmission of signals in the nervous system.

The most famous example of action potentials are found as nerve impulses in nerve fibers to muscles. Neurons, or nerve cells, are stimulated when the polarity across their plasma membrane changes. The polarity change, called an action potential, travels along the neuron until it reaches the end of the neuron.