1
|
Matsumoto A, Arisaka H, Hosokawa Y, Sakuraba S, Sugita T, Umezawa N, Kaku Y, Yoshida KI, Kuwana SI. Effect of carbamazepine and gabapentin on excitability in the trigeminal subnucleus caudalis of neonatal rats using a voltage-sensitive dye imaging technique. Biol Res 2015. [PMID: 26195075 PMCID: PMC4508818 DOI: 10.1186/s40659-015-0027-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Background The antiepileptic drugs
carbamazepine and gabapentin are effective in treating neuropathic pain and trigeminal neuralgia. In the present study, to analyze the effects of carbamazepine and gabapentin on neuronal excitation in the spinal trigeminal subnucleus caudalis (Sp5c) in the medulla oblongata, we recorded temporal changes in nociceptive afferent activity in the Sp5c of trigeminal nerve-attached brainstem slices of neonatal rats using a voltage-sensitive dye imaging technique. Results Electrical stimulation of the trigeminal nerve rootlet evoked changes in the fluorescence intensity of dye in the Sp5c. The optical signals were composed of two phases, a fast component with a sharp peak followed by a long-lasting component with a period of more than 500 ms. This evoked excitation was not influenced by administration of carbamazepine (10, 100 and 1,000 μM) or gabapentin (1 and 10 μM), but was increased by administration of 100 μM gabapentin. This evoked excitation was increased further in low Mg2+ (0.8 mM) conditions, and this effect of low Mg2+ concentration was antagonized by 30 μM DL-2-amino-5-phosphonopentanoic acid (AP5), a N-methyl-d-aspartate (NMDA) receptor blocker. The increased excitation in low Mg2+ conditions was also antagonized by carbamazepine (1,000 μM) and gabapentin (100 μM). Conclusion Carbamazepine and gabapentin did not decrease electrically evoked excitation in the Sp5c in control conditions. Further excitation in low Mg2+ conditions was antagonized by the NMDA receptor blocker AP5. Carbamazepine and gabapentin had similar effects to AP5 on evoked excitation in the Sp5c in low Mg2+ conditions. Thus, we concluded that carbamazepine and gabapentin may act by blocking NMDA receptors in the Sp5c, which contributes to its anti-hypersensitivity in neuropathic pain.
Collapse
Affiliation(s)
- Akiko Matsumoto
- Division of Anesthesiology, Department of Clinical Care Medicine, Kanagawa Dental College, Yokosuka, Kanagawa, 238-8580, Japan.
| | - Hirofumi Arisaka
- Division of Anesthesiology, Department of Clinical Care Medicine, Kanagawa Dental College, Yokosuka, Kanagawa, 238-8580, Japan.
| | - Yuki Hosokawa
- Department of Anesthesiology, Kitasato University School of Medicine, Sagamihara, Kanagawa, 252-0375, Japan.
| | - Shigeki Sakuraba
- Division of Anesthesiology, Department of Clinical Care Medicine, Kanagawa Dental College, Yokosuka, Kanagawa, 238-8580, Japan.
| | - Takeo Sugita
- Division of Anesthesiology, Department of Clinical Care Medicine, Kanagawa Dental College, Yokosuka, Kanagawa, 238-8580, Japan.
| | - Nobuo Umezawa
- Division of Anesthesiology, Department of Clinical Care Medicine, Kanagawa Dental College, Yokosuka, Kanagawa, 238-8580, Japan.
| | - Yuki Kaku
- Center for Medical Sciences, Ibaraki Prefectural University of Health Sciences, Ami, Inashiki-gun, Ibaraki, 300-0394, Japan.
| | - Kazu-ichi Yoshida
- Division of Anesthesiology, Department of Clinical Care Medicine, Kanagawa Dental College, Yokosuka, Kanagawa, 238-8580, Japan.
| | - Shun-ichi Kuwana
- Faculty of Health Sciences, Uekusa Gakuen University, Ogura-cho, Wakaba-ku, Chiba, 264-0007, Japan.
| |
Collapse
|