Neuroscience: Action Potentials, Synaptic Transmission, and Membrane Dynamics

What is diffusion in the context of cellular membranes?

The process by which substances move through a membrane due to concentration differences.

What role do ion channels play in cellular membranes?

They are membrane-spanning proteins that allow specific ions to pass through the channel.

What is ion selectivity in ion channels?

The ability of ion channels to allow only certain ions to pass through.

What is gating in relation to ion channels?

The opening and closing of ion channels in response to changes in membrane potential.

What is the function of ion pumps like the sodium-potassium pump?

To maintain the balance of ions across the membrane, which requires energy.

What is resting potential?

The electrical potential difference across a membrane when a neuron is not firing.

What is polarization in the context of membrane potential?

The state of having a difference in charge across the membrane.

What occurs during depolarization?

The membrane potential becomes less negative, moving towards zero.

What is the threshold in action potential generation?

The level of membrane depolarization required to trigger an action potential.

What does the term 'All-or-None' refer to in action potentials?

The principle that once the threshold is reached, an action potential will occur fully or not at all.

What is hyperpolarization?

An increase in membrane potential that makes the inside of the cell more negative than the resting potential.

What is the refractory period?

The time after an action potential during which a neuron cannot fire another action potential.

What happens during the rising phase of an action potential?

Sodium channels open, allowing sodium ions to flow into the cell, causing rapid depolarization.

What is the role of neurotransmitter receptors in synaptic transmission?

They convert chemical signals back into electrical signals in the postsynaptic neuron.

What is exocytosis in the context of neurotransmitter release?

The process by which vesicles fuse with the membrane to release neurotransmitters into the synaptic cleft.

What is the significance of voltage-gated calcium channels?

They open in response to depolarization, allowing calcium ions to enter the cell and trigger neurotransmitter release.

What is the function of ligand-gated ion channels?

They open in response to the binding of a neurotransmitter, allowing ions to flow across the membrane.

What are postsynaptic potentials?

Changes in the membrane potential of the postsynaptic neuron due to neurotransmitter binding.

What is the difference between excitatory and inhibitory postsynaptic potentials?

Excitatory potentials depolarize the postsynaptic membrane, while inhibitory potentials hyperpolarize it.