Final answer:
Norepinephrine is the neurotransmitter released at the postganglionic synapse of sympathetic nerves, which binds to adrenergic receptors on the target cell.
Step-by-step explanation:
The neurotransmitter released at the postganglionic synapse of sympathetic nerves is norepinephrine. This neurotransmitter is part of the sympathetic response and binds to adrenergic receptors on the target cell. Postganglionic sympathetic fibers primarily release norepinephrine, with the exception of the sweat glands which use acetylcholine.