Circuitry I

Which of the following terms describes a decrease in the membrane potential of a neuron?

Depolarization

Membrane potential

Leak channels

Hyperpolarization (correct)

What are the two major factors that underlie the resting membrane potential of a mammalian neuron?

Hyperpolarization and membrane potential

Leak channels and depolarization

Active properties of membranes and ion gradients

Concentrations of sodium and potassium (correct)

Which equation is used to calculate the reversal potential of an ion?

Nernst equation (correct)

Ion gradients equation

Goldman equation

Membrane potential equation

Which of the following terms is NOT associated with action potentials?

Concentration Signup and view all the answers

Which of the following is responsible for maintaining extracellular potassium levels in brain neurons?

Glial cells Signup and view all the answers

What can lead to hyper-excitability in neurons?

Increased extracellular potassium levels Signup and view all the answers

Which type of electrical response in neurons simply follows the direction of the injected current and decays back to baseline once the stimulus is stopped?

Passive response Signup and view all the answers

What is the term for a rapid and reversible active depolarization of the nerve cell membrane?

Action potential Signup and view all the answers

What is the coding mechanism used in neurons to transmit information, where frequency of action potential firing is used instead of amplitude?

Frequency coding Signup and view all the answers

In the figure below, what does the bottom panel plot?

Distance of the recording electrode from the stimulus Signup and view all the answers

Which ion has a higher concentration inside mammalian neurons compared to outside?

Potassium Signup and view all the answers

What is the resting membrane potential in neurons?

-70 mV Signup and view all the answers

What is the main factor that generates electrical potentials across neuronal membranes?

Differences in concentrations of specific ions inside and outside of the cells Signup and view all the answers

What is the main reason why passive conduction of electrical signals is not useful for conveying information over long distances?

Local nature of passive conduction Signup and view all the answers

Which equation can be used to calculate the equilibrium potential for an ion?

$E_{ion} = (RT/zF) \ln ([ion]_o/[ion]_i)$ Signup and view all the answers

What is the equilibrium potential for potassium (EK+) given a 10-fold difference in concentration between inside and outside the cell?

-58 mV Signup and view all the answers

If the concentration of potassium inside the cell is increased to 100 mM, what is the resulting EK+?

-116 mV Signup and view all the answers

What is the estimated permeability ratio of K+, Na+, and Cl- for a typical neuron at rest?

1 : 0.04 : 0.45 Signup and view all the answers