synthesised as a large precursor molecule at the cell soma and transported (potentially long distance) to release sites in dense core vesicles

co-released with classical neurotransmitters

slow postsynaptic effects

Actions terminated by macrophages

neuropeptides are synthesised from precursors, NPs uesed only once

NPs present at much lower concentrations in vesicles (10mM compared with 100mM)

Release requires a less intense stimulus and initially less calcium entry but ultimately neuropeptide release requires higher concentrations of Ca2+

Neuropeptides have much lower affinity for receptors

Neuropeptides are synthesised from much larger precursor molecules of at least 90 amino acids long

Pro-lactin undergoes a single cleavage in order to form its corresponding neuropeptide

A single precursor molecule can only give rise to one bioactive peptide

Substance P coexists with the excitatory neurotransmitter glutamate in primary afferents that respond ot painful stimulation

Signalling mediated through neuropeptin 1 receptors (NP1) - G protein coupled receptors

Substance P is also associated with anxiety, stress, neurogenesis, nausea

co-localises with neuropeptide Y - associated with excitatory signals