*3.1.1.1.1 Tetrodotoxin*

Tetrodotoxin (TTX) is a low-molecular-weight guanidine neurotoxin that acts as a specific blocker of voltage-gated sodium (NaV) channel [17]. TTX has neuroprotective properties by blocking NaV channels, preventing neuronal death by diminishing depolarization, cellular Na+ /Ca+2 exchange, and neuronal glutamate release [18].

The beneficial effects of TTX in preclinical studies include a reduction of white matter loss after SCI [17–19], promoting a motor function restoration. The effect of TTX is time-dependent [20]. The administration of TTX 15 minutes after a SCI helps to restore the function of hindlimbs [21]. Despite these promissory effects, there are some limitations for the use of TTX in patients, one of them is its toxicity. This may appear as a consequence of its systemic distribution and it can involve the blocking of diaphragmatic nerves ending in respiratory tract paralysis [17]. Even with previous findings, current studies are needed to improve its use in SCI.
