Crustacean Neuromuscular Signaling Modulators

Tetrodotoxin (TTX), myristoylated PKI_(14–22) and calcineurin autoinhibitory peptide (CiP) were purchased from Tocris Bioscience (Bristol, UK). BAPTA-AM, ryanodine and xestospongin C were from Cayman Chemical (Ann Arbor, MI). All other chemicals were purchased from Sigma-Aldrich (St. Louis, MI). DA was made fresh every 30min to minimize oxidation. PKI is an effective blocker of the PKA catalytic subunit in crustaceans [43 (link),46 (link),47 (link)]. CiP and FK506 block calcineurin activity in crustacean neurons at the indicated dosages [48 (link)–50 (link)]. In the spiny lobster, BAPTA, ryanodine and xestospongin C disrupt Ca²⁺ dynamics at the indicated dosages by chelating Ca²⁺, blocking ryanodine receptor function and inhibiting IP₃ receptor function, respectively [51 (link)].