Electrophysiology and Resting Membrane Potential Vocabulary

A set of vocabulary flashcards based on the electrophysiology and resting membrane potential lecture notes.

Sodium-potassium pump

An active membrane system that uses $ATP$ from mitochondria to pump sodium ions out of the neuron and potassium ions into the neuron, establishing unequal ion concentrations across the membrane.

Equilibrium potential

The charge that must be added to the inside of the cell to maintain the distribution or concentration of an ion across the membrane, assuming the ion is permeable to the membrane.

Potassium equilibrium potential

The equilibrium potential for potassium ions, specified in the lecture as $-80\,mV$.

Sodium equilibrium potential

The equilibrium potential for sodium ions, specified in the lecture as $+50\,mV$.

Membrane potential

The electrical charge across the membrane (inside relative to outside) determined by the equilibrium potentials of the ions in question relative to their permeability.

Resting membrane potential

The charge across the neuronal membrane when no active signal is occurring, typically $-70\,mV$, driven primarily by potassium being significantly more permeable than sodium at rest.

Permeability (in electrophysiology)

The functional equivalent of strength in electrophysiology; the more permeable an ion is across the membrane, the more its equilibrium potential controls the total charge across the membrane.

Depolarization

A change in the membrane potential that makes the charge inside the cell less negative or closer to zero.

Hyperpolarization

A change in the membrane potential that makes the charge inside the cell more negative or further away from zero.

Threshold

The specific membrane voltage level or degree of depolarization required to cause voltage-gated sodium channels to open.

Voltage-gated sodium channels

Membrane channels that stay closed until reaching threshold voltage, opening to allow sodium ions to flow into the neuron along their electrochemical concentration gradient.

Voltage-gated potassium channels

Membrane channels that open at the peak of an action potential and close relatively slowly, allowing potassium ions to flow out of the neuron along their electrochemical concentration gradient.

Nernst equation

A mathematical equation in neuroscience used to deduce the equilibrium potential of an ion based on various factors, including its concentrations across the membrane.