| Yazarlar (3) |
|
Kahramanmaraş Sütçü İmam Üniversitesi, Türkiye |
|
Çukurova Üniversitesi, Türkiye |
Prof. Dr. Yusuf Kenan DAĞLIOĞLU
Çukurova Üniversitesi, Türkiye |
| Özet |
| After a peripheral nerve injury, ion channel organization and the electrical properties of nerve fibers drastically change during the regeneration process. The present study was designed to compare the frequency-dependent characteristics of regenerating nerves in the presence of 4-aminopyridine (4-AP) and tetraethylammonium (TEA). The results showed that increasing the stimulus frequency produced a greater impulse blockade (frequency-dependent block--FDB) and distinct hyperpolarizing afterpotentials (HAPs) in regenerating nerves. In particular, regenerating sciatic nerves 15 days post-crush (dpc) were more sensitive to the frequency-dependent stimulations than 38-dpc and intact nerves in the presence or absence of drugs. The frequency-dependent effects of TEA on the compound action potentials (CAPs) appeared when TEA was applied to 4-AP-treated nerves. This shows that TEA-sensitive channels may not be masked by the myelin. 4-AP was here found to have more pronounced frequency-dependent effects on regenerating nerves than on intact nerves. Delayed depolarization (in 38-dpc: 22.6 +/- 1.3 mV and 47.52 +/- 3.63 ms, in intact: 12.0 +/- 1.9 mV and 88.51 +/- 4.72 ms) elicited by 4-AP resulted in an increase in FDBs and HAP amplitudes. These results suggest that 4-AP-sensitive channels may play important roles in frequency-dependent nerve conduction. Consequently, regenerating or myelin damaged nerves are more sensitive to repetitive firing with or without drug. An understanding of the frequency-dependent properties of regenerating nerves may be of value in the treatment of the nerve diseases. |
| Anahtar Kelimeler |
| slow sodium currents | fast and slow potassium channels | nerve injury | nerve regeneration | hyperpolarizing afterpotential |
| Makale Türü | Özgün Makale |
| Makale Alt Türü | SSCI, AHCI, SCI, SCI-Exp dergilerinde yayınlanan tam makale |
| Dergi Adı | PHARMACOLOGY |
| Dergi ISSN | 0031-7012 Wos Dergi Scopus Dergi |
| Dergi Tarandığı Indeksler | SCI-Expanded |
| Makale Dili | İngilizce |
| Basım Tarihi | 01-2004 |
| Cilt No | 72 |
| Sayı | 3 |
| Sayfalar | 157 / 166 |
| Doi Numarası | 10.1159/000080100 |