Each neurone synthesises either oxytocin or vasopressin (Fig. 5.6) as part of a larger precursor molecule (pro-oxyphysin and propressophysin, respectively). Unlike the oxytocin precursor molecule, the vasopressin precursor has a glycoprotein portion attached to the C-terminal end. Neurophysin-nonapeptide complexes migrate, as neurosecretory granules, along the axons of the neurones from each nucleus at a rate of lΓÇô3mm/h. The complex is then stored as granules at the end of the neuronal tracts to be released under the influence of specific stimuli.
