action potential

(noun)

A short-term change in the electrical potential that travels along a cell, such as a nerve or muscle fiber, and allows nerves to communicate.

Related Terms

(noun)

A short-term change in the electrical potential that travels along a cell (such as a nerve or muscle fiber); the basis of neural communication.

Related Terms

Examples of action potential in the following topics:

  • Stages of the Action Potential

    • Therefore, the neuron cannot reach action potential during this "rest period."
    • While an action potential is in progress, another cannot be generated under the same conditions.
    • The amplitude of an action potential is independent of the amount of current that produced it.
    • In other words, larger currents do not create larger action potentials.
    • The frequency of action potentials is correlated with the intensity of a stimulus.

  • Neurotransmitters

    • An action potential is necessary for neurotransmitters to be released, which means that neurons must reach a certain threshold of electric stimulation in order to complete the reaction.
    • Inhibitory neurotransmitters cause hyperpolarization of the postsynaptic cell (that is, decreasing the voltage gradient of the cell, thus bringing it further away from an action potential), while excitatory neurotransmitters cause depolarization (bringing it closer to an action potential).
    • The depolarizing (more likely to reach an action potential) or hyperpolarizing (less likely to reach an action potential) effect is also dependent on the receptor.
    • Glycine and GABA are considered inhibitory amino acids, again because their receptors cause hyperpolarization, making the receiving cell less likely to reach an action potential.

  • Mechanics of the Action Potential

    • Resting potential.
    • If the membrane potential reaches -55 mV, it has reached the threshold of excitation.
    • Eventually, the cell potential reaches +40 mV, or the action potential.
    • The action potential (which occurs as described above) travels along the membrane of the presynaptic cell until it reaches the synapse.
    • Synaptic responses summate in order to bring the postsynaptic neuron to the threshold of excitation, so it can fire an action potential (represented by the peak on the chart).

  • Neural Networks

    • If a stimulus creates a strong enough input signal in a nerve cell, the neuron sends an action potential and transmits this signal along its axon.
    • Charles Sherrington, in his influential 1906 book The Integrative Action of the Nervous System, developed the concept of stimulus-response mechanisms in much more detail, and behaviorism, the school of thought that dominated psychology through the middle of the 20th century, attempted to explain every aspect of human behavior in stimulus-response terms.
    • Neurons were found to be capable of producing regular sequences of action potentials ("firing") even in complete isolation.

  • The Limbic System

    • It helps the brain recognize potential threats and helps prepare the body for fight-or-flight reactions by increasing heart and breathing rate.
    • The basal ganglia appears to serve as a gating mechanism for physical movements, inhibiting potential movements until they are fully appropriate for the circumstances in which they are to be executed.

  • Cognitive Development in Adolescence

    • Metacognition provides the ability to plan ahead, see the future consequences of an action, and provide alternative explanations of events.
    • Adolescents reach a stage of social perspective-taking in which they can understand how the thoughts or actions of one person can influence those of another person, even if they personally are not involved.
    • The behavioral decision-making theory proposes that adolescents and adults both weigh the potential rewards and consequences of an action.

  • Evaluating the Humanistic Perspective on Personality

    • The humanistic perspective of personality theory is a holistic psychological perspective that attributes human characteristics and actions to free will and an innate drive for self-actualization .
    • This approach focuses on maximum human potential and achievement rather than psychoses and symptoms of disorder.
    • It explains human potential in a way that other theories cannot.

  • Humanistic Psychology

    • Humanistic psychology adopts a holistic view of human existence through explorations of meaning, human potential, and self-actualization.
    • The humanistic perspective is a holistic psychological perspective that attributes human characteristics and actions to free will and an innate drive for self-actualization.
    • This approach focuses on maximum human potential and achievement rather than psychoses and symptoms of disorder.
    • He believed that every person has a strong desire to realize his or her full potential—or to reach what he called "self-actualization."
    • Perhaps most importantly, the humanistic perspective emphasizes the need to strive for positive goals and explains human potential in a way that other theories cannot.

  • Altruism: Helping

    • The potential benefits from a relationship can be tangible, such as food, money, gifts, or housing.
    • Reciprocity involves an exchange of positive actions between people.
    • Reciprocal actions are important to social psychology as they can help explain the maintenance of social norms.

  • Arousal Theory of Motivation

    • Arousal theory expands upon drive-reduction theory by considering levels of arousal as potential motivators.
    • Arousal theory expands upon drive-reduction theory by taking into account levels of arousal as potential motivators.
    • Likewise, someone who is very impulsive and uninhibited might be very motivated to go buy a car on a moment's notice, as compared with someone who is very inhibited and has difficulty taking action.