Chronic and intermittent administration of systemic nitroglycerin in the rat induces an increase in the gene expression of CGRP in central areas: potential contribution to pain processing.

These findings point to the role of CGRP in the processes underlying migraine chronification and suggest a possible interaction with gamma-aminobutyrate (GABA) and glutamate transmission to induce/maintain central sensitization and to contribute to the dysregulation of descending pain system involved in chronic migraine.