Does the cell membrane depolarize or hyperpolarize to fire an action potential?
Depolarize
In order for an action potential to be generated, the cell membrane must depolarize.
During resting membrane potential, the inside of the cell is negatively charged relative to the outside. When a stimulus, such as a neurotransmitter or other chemical signal, binds to a receptor on the membrane, it causes an influx of positive ions (e.g. sodium or calcium) into the cell, which causes depolarization. If the depolarization reaches a certain threshold, voltage-gated ion channels are activated and allow an influx of more positive ions into the cell, causing an action potential to be fired.
Hyperpolarization, on the other hand, is a movement of ions out of the cell or influx of negative ions into the cell, which makes the inside of the cell more negative. This makes it more difficult for an action potential to be fired.
More Answers:
Understanding the Role of Ego: Importance, Balance, and Negative TraitsThe Impact of the Enlightenment on Attitudes Towards Mental Illness: From Harsh Stigma to Humane Treatment
Understanding Drive-Reduction Theory: Motivational Concepts Explained