Most of the released norepinephrine is

The release of norepinephrine primarily occurs at the synapse, where it travels across the synaptic cleft to bind to adrenergic receptors on the target cell. Following its action, most of the norepinephrine is taken back up into the nerve terminal through a process known as reuptake. This mechanism is crucial because it allows for the recycling of neurotransmitters, reducing the duration of their action and helping to terminate the signal effectively.

The reuptake process is facilitated by the norepinephrine transporter (NET), which is located on the presynaptic nerve terminal. By returning norepinephrine to its place of origin, the nervous system can maintain precise control over neurotransmitter levels and ensure that the signals are appropriately modulated.

While some of the norepinephrine may be metabolized by monoamine oxidase (MAO) or catechol-O-methyltransferase (COMT), or even diffuse into plasma, the primary regulatory mechanism for controlling the amount of norepinephrine available in the synapse is reuptake.