An electrical signal is converted into a chemical signal at a nerve terminal. When an action potential reaches a nerve terminal, it opens voltage-gated Ca²⁺ channels in the plasma membrane, allowing Ca²⁺ to flow into the terminal. The increased Ca²⁺ in the nerve terminal stimulates the synaptic vesicles to fuse with the plasma membrane, releasing their neurotransmitter into the synaptic cleft.  Fair Use and Copyright info