NEURONS ■ SYNAPTIC TRANSMISSION ■ NEUROCHEMICAL TRANSMISSION ■ THE MAINTENANCE OF NERVE CELL FUNCTION

potential of neurons; voltage-gated ion channels are re-sponsible for the action potential and the release of neuro-transmitter. 2. Ligand-gated ion channels cause membrane depolariza-tion or hyperpolarization in response to neurotransmit-ter. 3. Nongated ion channels are distributed throughout the neu-ronal membrane; voltage-gated channels are largely re-stricted to the axon and its terminals, while ligand-gated channels predominate on the cell body (soma) and den-dritic membrane. 4. Membrane conductance and capacitance affect ion flow in neurons. 5. An action potential is a transient change in membrane po-tential characterized by a rapid depolarization followed b