part 5: neuronal signaling Human anatomy and physiology
a ligand-gated channel
An ion channel that is stimulated to open by the binding of a small molecule such as a neurotransmitter.
voltage gated channels
Ion membrane channels that open and close in response to changes in membrane potential.
action potential
a neural impulse; a brief electrical charge that travels down an axon
Depolarization
change in a cell membrane potential from rest toward zero
Hyperpolarization
change in cell membrane potential below resting potential (<-70mV)
Neurotransmitters
chemical messengers that cross the synaptic gaps between neurons
membrane potential
distribution of charge across the cell membrane, based on the charges of ions
leakage channels
ion channel that opens randomly and is not gated to a specific event, also known as a non-gated channel
mechanically gated channels
ion channel that opens when a physical event directly affects the structure of the protein
Repolarization
return of the membrane potential to its normally negative voltage at the end of the action potential
resting membrane potential
the electrical charge of a neuron when it is not active