Hyperpolarization is when a neuron’s membrane potential (mV) becomes more negatively charged (value less than 0) at a specific location on the cell membrane. As a result, the neuron is less likely to fire an action potential.
![Image of the process of hyperpolarization.](https://laymn.com/wp-content/uploads/2021/10/hyperpolarization-1024x535.jpg)
The permeability of the membrane to ions changes with depolarization (towards 0) or hyperpolarization (away from 0). The typical neuronal resting potential is approximately -90 mV for the extracellular fluid.
Membrane potential | From -70 to -90mV |
Charge | Negative charge increases |
Major Cause | Opening of channels that let K+ out of the cel or CI- ions into the cell |
Flow of Positive Ions | Out of cell |
Na+ K+ ions | K+ ions flow out of the cell |
Na+ channels | Closed |
K+ channels | Opened |
Interesting comment in Khan Academy:
![](https://laymn.com/wp-content/uploads/2021/10/image.png)
References:
Felten, D. L., O’Banion, M. K., & Maida, M. E. (2021). Netter’s Atlas of Neuroscience E-Book. Elsevier Health Sciences.