What do we already know about this topic?
Previous studies suggest calcitonin gene-related peptide (CGRP) plays a critical role in migraine pathophysiology, but the location and mechanisms of CGRP in migraine are still unknown.
A high number of CGRP binding sites are located in the cerebellum, which serves as a sensory and motor integrative center, and is activated during a migraine attack.
CGRP is densely distributed in the Purkinje cells (PCs) and cerebellum medial nucleus, suggesting that CGRP may act on the cerebellum to induce migraine-like behaviors.
How was this study conducted?
CGRP expression was measured in the cerebellum of C57BL/6 mice using qPCR and immunohistochemistry, and in calca-cre mice using a cre-dependent viral reporter (AAV-EF1a-DIO-EYFP).
The mice were injected with CGRP into the cerebellar vermis V and fastigial nucleus and tested in the light-dark assay to evaluate light aversion.
An open field test was used to evaluate anxiety and locomotion, sensitivity to plantar Von Frey filaments, and a squint test was used to evaluate pain.
A cerebellar CGRP sensitized mouse model (L7/hRAMP1) was created to further test the role of cerebellar CGRP in migraine.
Rats were injected with CGRP into crus I in the cerebellar cortex and were run in an interval estimation task.