Protein synthesis is required for initiation and maintenance of BDNF-mediated protection from NO-induced growth-cone collapse
| Treatment | Axons with growth cones (%) | |
|---|---|---|
| Initiation | Maintenance | |
| BDNF | 84 ± 2 | 68 ± 4 |
| BSA + NO | 39 ± 4 | 37 ± 3 |
| BDNF + NO | 80 ± 4 | 62 ± 3 |
| Cyclo + BDNF | 83 ± 2 | 64 ± 9 |
| Cyclo + BDNF + NO | 43 ± 2* | 34 ± 5* |
| Puro + BDNF | 77 ± 3 | 68 ± 2 |
| Puro + BDNF + NO | 36 ± 21-160 | 43 ± 2* |
To test the role of protein synthesis in initiation of BDNF-mediated protection, retinal explant cultures were pretreated with 2 μg/ml cycloheximide (Cyclo) or 7.5 μg/ml puromycin (Puro) for 1 hr before treatment with BDNF for 1 hr (Initiation column). To test the role of protein synthesis in maintenance of BDNF-mediated protection, cultures raised in continuous BDNF for 24 hr were treated with cycloheximide or puromycin for 2 hr (Maintenance column). A 10 min treatment with 750 μm NOC-7 was used to deliver NO to cultures. Cultures were then fixed and scored for growth-cone collapse (n ≥ 5 cultures scored in each group). Pretreatment or post-treatment with either protein synthesis inhibitor blocked the protective effects of BDNF.
↵* p < 0.01;
↵F1-160 p< 0.001; BDNF + NOC-7 versus BDNF + drug + NOC-7.