What are the key differences between ligand-gated ion channels and voltage-gated ion channels in terms of their mechanisms of activation and regulation?

Ligand-gated ion channels are activated by binding of specific molecules (ligands) to the channel, while voltage-gated ion channels are activated by changes in the electrical potential across the cell membrane. Ligand-gated channels are regulated by the presence of ligands, while voltage-gated channels are regulated by changes in membrane potential.