Resting potential

Definition

Resting potential refers to the electrical charge difference across a neuron's membrane when it is not actively transmitting a signal, typically around -70 mV. This state is essential for maintaining the neuron's readiness to respond to stimuli, allowing for rapid changes in membrane potential during neuronal communication. The resting potential is primarily established by the distribution of ions, such as sodium and potassium, across the membrane, which influences how neurons communicate and transmit information across synapses.

5 Must Know Facts For Your Next Test

1. The resting potential is maintained by the sodium-potassium pump, which actively transports sodium ions out of the cell and potassium ions into the cell.
2. The permeability of the neuron's membrane to different ions is what primarily contributes to the negative charge inside relative to the outside.
3. When a neuron is at resting potential, it is more permeable to potassium ions than sodium ions, which helps maintain its negative charge.
4. The resting potential is crucial for the generation of action potentials, as a sufficient depolarization must occur for a neuron to fire.
5. Disruptions in resting potential can lead to abnormal neuronal activity and are associated with various neurological disorders.

Review Questions

• How does resting potential prepare a neuron for communication with other neurons?
  • Resting potential prepares a neuron for communication by maintaining a stable negative charge inside the cell, which allows for quick changes in membrane potential when stimulated. When a signal arrives, it can depolarize the membrane, leading to the generation of an action potential. This readiness is essential for efficient signaling, as it ensures that neurons can rapidly respond to incoming signals and transmit information effectively.
• Discuss the role of ion channels in establishing and maintaining resting potential in neurons.
  • Ion channels are critical in establishing and maintaining resting potential by controlling the flow of ions across the neuron's membrane. At resting potential, potassium channels allow potassium ions to move out of the cell, while sodium channels remain mostly closed, preventing sodium from entering. This selective permeability creates a charge difference, with more positive ions outside compared to inside, thus maintaining the negative resting potential necessary for neuronal communication.
• Evaluate the implications of altered resting potential on neuronal function and communication within the nervous system.
  • Altered resting potential can significantly impact neuronal function and communication by disrupting the balance of ionic concentrations necessary for generating action potentials. If resting potential becomes too positive or too negative due to ion channel dysfunction or other factors, neurons may become less responsive or overly excitable. This imbalance can lead to various neurological disorders, such as epilepsy or paralysis, highlighting how crucial maintaining proper resting potential is for normal nervous system operation.

Related terms

Action potential: A rapid change in membrane potential that occurs when a neuron sends a signal along its axon, leading to the transmission of information.

Ion channels: Proteins that span the neuronal membrane and allow specific ions to enter or exit the neuron, playing a crucial role in establishing and altering membrane potential.

Neurotransmitters: Chemical messengers released by neurons at synapses to communicate with other neurons, influencing their activity and signaling.