CGRP receptor antagonism impairs microglial anti-inflammatory function: IL-4 supplementation as a compensatory strategy for migraine.

This study investigates the role of calcitonin gene-related peptide (CGRP) in migraine treatment. CGRP is a target for migraine therapies. Researchers found a surprising effect of CGRP receptor antagonists. These drugs relieve migraine pain but may reduce microglial anti-inflammatory activity. Microglia are immune cells in the brain that help with inflammation. In chronic migraine mouse models, treatment with a CGRP antagonist did not increase anti-inflammatory markers. This suggests that blocking CGRP could weaken the brain's natural healing response. To address this issue, researchers tested IL-4, a molecule that promotes inflammation reduction. They found that IL-4 restored microglial function and worked well with the CGRP antagonist. Together, they provided better pain relief than either treatment alone. This study highlights the complex relationship between CGRP and microglial function in migraine management and suggests new treatment strategies. Clinical relevance: This research indicates that combining CGRP antagonists with IL-4 could enhance migraine treatment effectiveness by improving anti-inflammatory responses in the brain.