1
|
Toyoda KI, Okano H, Bamba H, Hisa Y, Oomura Y, Imamura T, Furukawa S, Tooyama I. Comparison of FGF1 (aFGF) expression between the dorsal motor nucleus of vagus and the hypoglossal nucleus of rat. Acta Histochem Cytochem 2006; 39:1-7. [PMID: 17460766 PMCID: PMC1831852 DOI: 10.1267/ahc.05047] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2005] [Accepted: 12/18/2005] [Indexed: 11/22/2022] Open
Abstract
Neurons in the dorsal motor nucleus of the vagus (DMNV) are more severely affected by axonal injury than most other nerves, such as those of the hypoglossal nucleus. However, the mechanism underlying such a response remains unclear. In this study, we compared the expression of fibroblast growth factor 1 (FGF1), a neurotrophic factor, between the DMNV and the hypoglossal nucleus by RT-PCR and immunohistochemical analyses. RT-PCR showed that the level of FGF1 mRNA expression in the DMNV was lower than that in the hypoglossal nucleus (P<0.01). Immunohistochemistry revealed that FGF1 was localized to neurons. FGF1-positive neurons in large numbers were evenly distributed in the hypoglossal nucleus, whereas FGF1-positive neurons were located in the lateral part of the DMNV. Double immunostaining for FGF1 and choline acetyltransferase demonstrated that 22.7% and 78% of cholinergic neurons were positive for FGF1 in the DMNV and hypoglossal nucleus, respectively. A tracing study with cholera toxin B subunit (CTb) demonstrated that cholinergic neurons sending their axons from the DMNV to the superior laryngeal nerve were FGF1-negative. The results suggest that the low expression of FGF1 in the DMNV is due to severe damage of neurons in the DMNV.
Collapse
Affiliation(s)
- Ken-ichiro Toyoda
- Molecular Neuroscience Research Center, Shiga University of Medical Science, Setatukinowa-cho, Otsu 520–2192, Japan
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kyoto 602–8566, Japan
| | - Hiroyuki Okano
- Molecular Neuroscience Research Center, Shiga University of Medical Science, Setatukinowa-cho, Otsu 520–2192, Japan
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kyoto 602–8566, Japan
| | - Hitoshi Bamba
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kyoto 602–8566, Japan
| | - Yasuo Hisa
- Department of Otolaryngology-Head and Neck Surgery, Kyoto Prefectural University of Medicine, Kawaramachi-Hirokoji, Kyoto 602–8566, Japan
| | - Yutaka Oomura
- Department of Physiology, School of Medicine, Kyushu University, Fukuoka 812–8582, Japan
| | - Toru Imamura
- Signaling Molecules Research Laboratory, National Institute of Advanced Industrial Science and Technology (AIST), 1–1–1 Higashi, Tsukuba, Ibaraki 305–8566, Japan
| | - Shoei Furukawa
- Laboratory of Molecular Biology, Gifu Pharmaceutical University, Mitahora-higashi 5–6–1, Gifu 502–8585, Japan
| | - Ikuo Tooyama
- Molecular Neuroscience Research Center, Shiga University of Medical Science, Setatukinowa-cho, Otsu 520–2192, Japan
- Correspondence to: Ikuo Tooyama, Professor, Molecular Neuroscience Research Center, Shiga University of Medical Science, Setatsukinowa-cho, Otsu 520–2192, Japan. E-mail:
| |
Collapse
|