Table 1.
In vivo studies of neurotrophic factors in the inner ear.
| Species | Method of deafening | Period of deafness | Neurotrophin used | Period of treatment | Method of treatment | Electrical stimulation | Major finding1 | Reference |
|---|---|---|---|---|---|---|---|---|
| Guinea pig | Neomycin (in cannula)2 | 1 day | NGF | 2 weeks | Osmotic pump | No | ↑ nerve fibre survival | (Schindler et al., 1995) |
| Guinea pig | Neomycin (in cannula)2 | 2 weeks | NGF | 2 weeks (after 2 weeks of AP) | Osmotic pump | No | ↑ survival in basal turn | (Shah et al., 1995) |
| Guinea pig | Kanamycin/Ethacrynic acid | 5 days | BDNF and/or NT-3 | 8 weeks | Osmotic pump | No | ↑ survival; resprouting axons | (Staecker et al., 1996) |
| Guinea pig | Amikacin (in cannula)2 | 24 hours | NT-3 | 2 weeks | Osmotic pump | No | ↑ survival; resprouting axons | (Ernfors et al., 1996) |
| Guinea pig | Kanamycin/Ethacrynic acid | 7 days | BDNF | 2 weeks | Osmotic pump | No | ↑ survival | (Miller et al., 1997) |
| 4 days | BDNF + NT-3 + GDNF + CNTF | 28 days | resprouting axons | |||||
| Guinea pig | Noise | 4 days | GDNF | 3 weeks | Osmotic pump | No | ↑ survival | (Ylikoski et al., 1998) |
| Mouse | Neomycin | None | BDNF | 2 or 4 weeks | Herpes simplex viral vector | No | ↑ survival | (Staecker et al., 1998) |
| Guinea pigs | Aminoglycoside/diuretic | 4 or 7 days | GDNF | 24 or 21 days | Adenoviral vectors | No | ↑ survival | (Yagi et al., 2000) |
| Guinea pig | Neomycin (in cannula)2 | 2 days | BDNF + CNTF | 26 days | Osmotic pump | No; EABRs measured | ↑ survival; ↓ thresholds |
(Shinohara et al., 2002) |
| Guinea pig | Kanamycin/Ethacrynic acid | 5 days | GDNF | 39 days (36 days ES) | Adenoviral vectors | Yes | ↑ survival with GDNF+ES | (Kanzaki et al., 2002) |
| Guinea pig | Kanamycin/Frusemide | 5 days | BDNF | 28 days | Osmotic pump | No | ↑ survival; ↓ survival after BDNF removed |
(Gillespie et al., 2003) |
| Guinea pig | Neomycin (in cannula)2 | 2 weeks | BDNF + CNTF | 27 days | Osmotic pump | No; EABRs measured | ↑ survival | (Yamagata et al., 2004) |
| Neomycin (middle ear) | 6 weeks | BDNF + CNTF | ↑ survival; but less pronounced | |||||
| Guinea pig | Kanamycin/Frusemide | 14 days | BDNF, NT-3, NT-4/5 or NGF | 28 days | Osmotic pump | No | ↑ survival | (Gillespie et al., 2004) |
| Guinea pig | Kanamycin/Frusemide | 28 days | NT-3 | 7 days | Single pulse infusion | No | ↑ soma size; no survival effect | (Richardson et al., 2005) |
| NT-3 + BDNF | 28 days | Osmotic pump | ↑ survival; ↑ soma size |
|||||
| Guinea pig | Kanamycin/Frusemide | 5 days | BDNF | 28 days | Osmotic pump | Yes | ↑ survival; ↓ thresholds |
(Shepherd et al., 2005) |
| Rat | Gentamycin/Frusemide | 2 weeks | BDNF | 28 days | Osmotic pump | No | ↑ survival; ↑ soma size |
(McGuinness and Shepherd, 2005) |
| Guinea pig | Kanamycin/Frusemide | 5 days or 33 days | BDNF + NT-3 | 28 days | Osmotic pump | No | ↑ survival; resprouting axons | (Wise et al., 2005) |
1
As compared to deafened, untreated controls and/or deafened, sham-operated cohorts
2
In these cases, the animals underwent surgery for aminoglycoside exposure and osmotic pump implantation at the same time. The cannula of the drug delivery system was filled with the aminoglycoside; one end was inserted into the cochlea, while the other was attached to the osmotic pump.