Background & Aims
This study aimed to alleviate neuronal hyper-excitation caused by experimentally induced pulpitis by inhibiting the activity of peripheral voltage-gated sodium channel 1.7 (Nav1.7), which results in neuronal overexpression in the trigeminal ganglion (TG).
Methods
The pulp of rat maxillary molars was exposed with allyl isothiocyanate (AITC) to induce acute pulpitis. Rats were assigned into three groups randomly: a control group where the pulp was exposed to saline, a pulpitis group where the pulp was exposed to AITC, and a ProTxll group where the pulp was inflamed after AITC exposure and treated with a selective Nav 1.7 blocker (ProTxll). After three days, in vivo optical imaging was performed in the TG to observe the activity of neurons through membrane potential changes, and voltage sensitive dye (VSD) imaging was used to observe the activity of neurons. Immunostaining was used to compare the expression of Nav1.7 in the TG, while western blot was used to observe changes in signal transduction pathway responses.
Results
A wider and higher pattern of neural activation was observed in pulpitis-induced neuronal excitation compared to the control group. After applying ProTxII, a Nav1.7 inhibitor, for 30 minutes to confirm its alleviating effect on pulpitis-induced neuronal excitation, neuronal activation in the TG was significantly reduced compared to before ProTxII treatment.
Conclusions
This study demonstrates the neurological changes observed in the TG of a pulpitis model. It confirms, through histological and molecular biological evidence, that increases in Nav1.7 due to pulpitis increase neuronal excitation. Additionally, it shows that selective inhibition of Nav1.7 can effectively modulate neuronal activity. The results indicate that pulpitis causes an increase in Nav1.7 in the TG. Modulating the activity of Nav1.7 may be an effective way to reduce pain in patients with pulpitis in the clinic.
This work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (MOE) (NRF-2016R1D1A3B20-08194).
References
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Presenting Author
Kyunghee Lee
Poster Authors
Topics
- Specific Pain Conditions/Pain in Specific Populations: Orofacial Pain