Impairment of trigeminal nociceptors develops slowly; loss of TRPV1-mediated CGRP release and the lack of meningeal vasodilatation upon TRPV1 stimulation cannot be observed shortly after the induction of diabetes, which may be explained by the slow decrease in neuronal peptide levels after treatment with streptozotocin. Here, TRPV1 is linked to diabetes mellitus.