Activation of the Transcription Factor NF-κB in the Nucleus Trigeminalis Caudalis in an Animal Model of Migraine

The infusion of nitroglycerin (NTG) induces an inflammatory state in perivascular meningeal tissues of rat via the activation, inter alia, of nuclear factor kappa B (NF-κB). This phenomenon has been related to the mechanisms involved in the pathophysiology of migraine, a common neurovascular disorder. In the present study, we sought to elucidate whether NF-κB activation might have a role in the determinism of migraine attacks also at the neuronal level. Therefore, we investigated the transcriptional activity of NF-κB in the brainstem of rats systemically injected with NTG and killed 4 h later. Activation of NF-κB in brain areas was detected by means of both the immunohistochemical technique and the Western blot analysis. A significant increase of nuclear immunostaining of p65, an indicator of NF-κB activation, was detected in lamina I and II of nucleus trigeminalis caudalis in rats injected with NTG when compared with the control group. Western blot analysis confirmed the activation of the NF-κB pathway showing an increase in the optical density of p65 in nuclear extracts of lower brainstem of rats injected with the nitric oxide (NO) donor. The present study contributes to expand on our understanding of the complex mechanisms by which NTG may trigger migraine-like headaches in migraineurs. Furthermore, these findings pave the way to new bio-molecular and pharmacological avenues for the development of innovative migraine therapies.