BMS325 – Cellular Neurobiology : Final Exam Review (Section I)

Flashcards covering key vocabulary terms related to cellular neurobiology, including neuron structure, membrane properties, action potentials, synaptic transmission, and synaptic plasticity.

Neuron

A nerve cell; the basic building block of the nervous system.

Cell Body (Soma)

Contains the nucleus and other organelles; integrates signals.

Dendrite

Branchlike parts of a neuron that are specialized to receive information.

Axon

A long, thin fiber that transmits signals away from the cell body to other neurons or target cells.

Axon Terminal

The endpoint of a neuron where signals are transmitted to other neurons or target cells.

Axon Initial Segment

The section of the axon where the action potential is initiated.

Myelin

A fatty substance that insulates axons and speeds up signal transmission.

Neuronal Polarization

The unequal distribution of ions across the neuronal membrane, creating a voltage difference.

Charge

A fundamental property of matter that causes it to experience a force in an electromagnetic field.

Current

The flow of electrical charge carriers, usually electrons or ions, in a circuit or across a membrane.

Voltage

The difference in electrical potential between two points, measured in volts.

Resistance

A measure of how difficult it is for current to flow through a material or circuit.

Conductance

A measure of how easily current flows through a material or circuit.

Depolarization

A change in a cell's membrane potential, making it more positive.

Hyperpolarization

A change in a cell's membrane potential, making it more negative.

Equilibrium Potential

The membrane potential at which the electrical and chemical forces are equal and opposite, resulting in no net ion flow.

Channel

A protein that forms a pore in the cell membrane, allowing specific ions to pass through.

Transporter

A protein that binds to a specific molecule and carries it across the cell membrane.

Resting Membrane Potential

The electrical potential difference across the plasma membrane of a cell when it is not stimulated or conducting an impulse.

Nernst Potential

The equilibrium potential for a single ion, determined by the Nernst equation.

Ohm's Law

The relationship between voltage, current, and resistance (V = IR).

Reversal Potential

The membrane potential at which the direction of ion flow reverses.

Driving Force

The difference between the membrane potential and the equilibrium potential for an ion.

Conductance

A measure of the permeability of a membrane to an ion.

Threshold

The membrane potential at which an action potential is triggered.

Rising Phase

The initial phase of an action potential, characterized by a rapid increase in membrane potential.

Repolarization Phase

The phase of an action potential in which the membrane potential returns to its resting value.

After Hyperpolarization

The brief period of hyperpolarization that follows the repolarization phase of an action potential.

Absolute Refractory Period

The period during which another action potential cannot be triggered, regardless of the stimulus intensity.

Relative Refractory Period

The period during which a stronger-than-normal stimulus is required to trigger another action potential.

Voltage-Gated Sodium Channels (NaV)

Ion channels that are selectively permeable to sodium ions and open in response to changes in the membrane potential.

Voltage-Gated Potassium Channels (KV)

Ion channels that are selectively permeable to potassium ions and open in response to changes in the membrane potential.

Two-Electrode Voltage Clamp

A technique used to control the membrane potential of a cell while measuring the resulting current.

Synapse

A junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter.

Chemical Synapse

A synapse where communication between neurons occurs via the release of neurotransmitters.

Electrical Synapse

A synapse where communication between neurons occurs via direct electrical coupling through gap junctions.

Synaptic Vesicles

Small, spherical sacs in the presynaptic terminal that store neurotransmitters.

SNARE Complex

A protein complex that mediates the fusion of synaptic vesicles with the presynaptic membrane.

Synaptotagmins

Proteins that bind calcium ions and trigger synaptic vesicle fusion.

Quantal Theory of Release

The concept that neurotransmitters are released in discrete packets or quanta.

Ionotropic Receptors

Receptor proteins that form ion channels and are directly activated by ligand binding.

Metabotropic Receptors

Receptor proteins that activate intracellular signaling pathways via G proteins.

Inhibition

The process of reducing or preventing neuronal activity.

Hyperpolarization

A change in a cell's membrane potential, making it more negative.

G-Proteins

Proteins mediate intracellular signaling cascades.

Kinases

Enzymes that add phosphate groups to proteins.

Phosphatases

Enzymes that remove phosphate groups from proteins.

Synaptic Plasticity

The ability of synapses to strengthen or weaken over time, in response to increases or decreases in their activity.

Long-Term Potentiation (LTP)

A persistent strengthening of synapses based on recent patterns of activity.

Long-Term Depression (LTD)

A persistent weakening of synapses based on recent patterns of activity.

Endocannabinoids

Lipid-based retrograde neurotransmitters that modulate synaptic strength.

NMDA Receptors

Glutamate receptors that act as coincidence detectors and are critical for LTP induction.

CREB Transcription Factors

Proteins that bind to specific DNA sequences and regulate gene expression.