Tetrodotoxin ttx

Pentylone⋅HCl and Methylone⋅HCl were obtained from Cayman Chemical. 3,4-methylenedioxymethamphetamine (MDMA) HCl was obtained from NIDA Drug Supply. The MDMA analog was obtained from Fox Chase Chemical Diversity Center (Doylestown, PA, United States). Drugs were dissolved in physiological saline for the i.v. routes of administration. Dosing is expressed as the salt.
We purchased tetrodotoxin (TTX) from Biotium (Hayward, CA, United States), and AP-5, CGP55845A and DNQX, U-50488, and nor-binaltorphimine from Tocris (Bristol, United Kingdom) for the electrophysiological recordings. Stock solutions of the drugs were prepared in either distilled water or dimethyl sulfoxide (DMSO) and added to the bath solution to achieve the desired concentration.

Tetrodotoxin (TTX; Biotium Inc., Fremont, CA, USA) was used at a concentration of 10 nM (low TTX) or 200 nM (high TTX) and Nickel chloride (NiCl; Sigma-Aldrich, Oakville, ON, Canada) was used at a concentration of 1 mM in ACSF. Extracellular Ca²⁺ was also manipulated by changing its concentration in the ACSF (3 or 0 mM) while keeping the concentration of other positively-charged divalent ions (e.g., Mg²⁺) constant.