hyperpolarization

biology

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June 29, 2026

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Hyperpolarization is a biological process that occurs in electrically excitable cells, such as neurons. It involves an increase in the electrical potential difference across the cell membrane, making the interior of the cell more negative than its usual resting potential. The resting potential in neurons typically ranges from -60 to -95 millivolts, with the inside of the cell being negatively charged relative to the outside.1

This change in potential is often caused by the outward movement of positively charged ions, like potassium, or the inward movement of negatively charged ions. For instance, certain potassium channels, when activated, can lead to hyperpolarization, slowing down the repetitive firing of nerve impulses. Conversely, depolarization occurs when the inside of the cell becomes less negative, which is crucial for transmitting nerve impulses. Hyperpolarization, therefore, represents a state where the cell is further from its threshold for firing an action potential.213

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nervous system
The neuronal membrane
…even more negative is called hyperpolarization, while any change tending to make it less negative is called depolarization.
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…even more negative is called hyperpolarization, while any change tending to make it less negative is called depolarization.
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postsynaptic potential
Hyperpolarization—that is, an increase in negative charge on the inside of the neuron—constitutes an inhibitory PSP, because it inhibits the neuron from firing an impulse. Depolarization—a decrease in negative charge—constitutes an excitatory PSP because, if the neuron reaches the critical threshold potential, it can excite…
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Hyperpolarization—that is, an increase in negative charge on the inside of the neuron—constitutes an inhibitory PSP, because it inhibits the neuron from firing an impulse. Depolarization—a decrease in negative charge—constitutes an excitatory PSP because, if the neuron reaches the critical threshold potential, it can excite…
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resting potential
…cell is said to be hyperpolarized. If the inside of the cell becomes less negative (i.e., the potential decreases below the resting potential), the process is called depolarization.
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…cell is said to be hyperpolarized. If the inside of the cell becomes less negative (i.e., the potential decreases below the resting potential), the process is called depolarization.
Read More