BDNF and amyotrophic lateral sclerosis: The fact that TTC and BDNF-TTC can be transported through motoneurons to induce a later onset of symptoms, improve motoneuron survival and extend the survival of SOD1G93A mice suggests that the naked DNA-mediated intramuscular delivery of TTC and BDNF-TTC fusion molecules promotes neuroprotective effects in the SOD1G93A murine model of ALS.