Neurophysiology Flashcards

Flashcards covering key vocabulary and concepts in neurophysiology, including membrane potential, action potentials, synaptic transmission, and electrical activity measurement.

Neurophysiology

The study of the function of the nervous system via electrical and chemical signals.

Electrophysiology

The study of the electrical properties of cells.

Resting membrane potential

The electrical charge difference across the cell membrane of a neuron when it is not actively signaling; typically around -65 mV.

Ionic forces

Forces that drive ion movement across the cell membrane, including chemical (concentration gradient) and electrostatic pressure.

Na+/K+ pumps

Proteins that actively transport Na+ ions out of the cell and K+ ions into the cell, helping to maintain the resting membrane potential.

K+ ion channels

Pores in the cell membrane that allow K+ ions to pass through, contributing to the resting membrane potential.

K+ equilibrium potential

The membrane potential at which the electrical and chemical forces on an ion are balanced, resulting in no net movement of the ion.

Hyperpolarization

An increase in membrane potential, making the inside of the cell more negative.

Depolarization

A decrease in membrane potential, making the inside of the cell less negative.

Action potential

A brief, all-or-nothing electrical signal that travels down the axon of a neuron.

Voltage-gated Na+ channels

Ion channels that open or close in response to changes in membrane potential; critical for action potential generation.

Absolute refractory period

The period after an action potential when another action potential cannot be generated due to inactivated Na+ channels.

Relative refractory period

The period after an action potential when a stronger-than-normal stimulus is required to generate another action potential.

Optogenetics

A technique using light to control the activity of neurons, typically by introducing light-sensitive ion channels.

Channelrhodopsin (ChR2)

A light-gated cation channel derived from algae that opens in response to blue light, allowing researchers to trigger action potentials in neurons.

EPSPs (Excitatory postsynaptic potentials)

Postsynaptic potentials that depolarize the membrane, increasing the likelihood of an action potential.

IPSPs (Inhibitory postsynaptic potentials)

Postsynaptic potentials that hyperpolarize the membrane, decreasing the likelihood of an action potential.

Spatial summation

The summing of potentials from different locations on the neuron to determine whether an action potential will be initiated.

Temporal summation

The summing of potentials arriving at different times on the neuron to determine whether an action potential will be initiated.

Degradation

Rapid breakdown and inactivation of neurotransmitters by enzymes.

Reuptake

The clearing/recycling of neurotransmitters from the synapse by transporters in the presynaptic terminal or nearby glia.

Ligands

Molecules that bind to receptors and activate or block them, including neurotransmitters and drugs.

Axo-dendritic synapse

Synapse between an axon terminal and a dendrite.

Axo-somatic synapse

Synapse between an axon and a cell body (soma).

Axo-axonic synapse

Synapse between two axons.

Electroencephalogram (EEG)

A recording of spontaneous brain potentials (brain waves).

Event-related potentials (ERPs)

EEG responses to a single stimulus, such as a flash of light or loud sound.

Epilepsy

A brain disorder characterized by seizures, which are waves of abnormally synchronous electrical activity in the brain.

Tonic-clonic seizure (Grand mal seizure)

Abnormal EEG activity throughout the brain; loss of consciousness.

Simple partial seizure (Petit mal seizure)

Brain waves show patterns of seizure activity for 5 to 15 seconds, may occur several times a day.