ABSTRACT
Motion-induced anxiety and agoraphobia are more frequent symptoms in patients with vestibular migraine than migraine without vertigo. The neuropeptide calcitonin gene-related peptide (CGRP) is a therapeutic target for migraine and vestibular migraine, but the link between motion hypersensitivity, anxiety, and CGRP is relatively unexplored, especially in preclinical mouse models. To further examine this link, we tested the effects of systemic CGRP and off-vertical axis rotation (OVAR) on elevated plus maze (EPM) and rotarod performance in male and female C57BL/6J mice. Rotarod ability was assessed using two different dowel diameters: mouse dowel (r = 1.5 cm) versus rat dowel (r = 3.5 cm). EPM results indicate CGRP increased anxiety indexes and time spent in the closed arms in females but not males, while OVAR increased anxiety indexes and time spent in the closed arms in both sexes. The combination of CGRP and OVAR elicited even greater anxiety-like behavior. On the rotarod, CGRP reduced performance in both sexes on a mouse dowel but had no effect on a rat dowel, whereas OVAR had a significant effect on the rat dowel. Rotarod performance is influenced by dowel diameter, with larger dowels presenting greater challenges on balance function. These results suggest that both CGRP and vestibular stimulation induce anxiety-like behavior and that CGRP affects dynamic balance function in mice depending on the type of challenge presented. Findings highlight the potential translation of anti-CGRP receptor signaling therapeutics for treating motion hypersensitivity and motion-induced anxiety that manifests in vestibular migraine. Significance statement: Anxiety is very common in patients with dizziness and vestibular migraine (VM). Elevated CGRP levels have been linked to migraine symptoms of increased light and touch sensitivity in mice and humans and we wondered if a systemic injection of CGRP into mice would increase anxiety and imbalance; and if mice further exposed to a vestibular stimulus would have their anxiety measures sharpened. We observed a female preponderance in both CGRP and motion-induced anxiety-like behaviors, suggesting that the role of CGRP in migraine's anxiety symptoms can be recapitulated in the mouse. Our findings suggest that CGRP signaling has a pertinent role in motion-induced anxiety and dynamic imbalance, and warrants the potential use of anti-CGRP therapies for the treatment of these symptoms.
