Sodium ascorbic acid

Rats were deeply anesthetized with isoflurane (Kent Scientific) and euthanized by decapitation. The brain was rapidly dissected and glued on a platform submerged in an ice-cold oxygenated (95% O₂/5% CO₂) cutting solution containing (in mM): 206 sucrose (Sigma-Aldrich), 10 D-glucose (Sigma-Aldrich), 1.25 NaH₂PO₄ (Sigma-Aldrich), 26 NaHCO₃ (Sigma-Aldrich), 2 KCl (Fisher Chemical), 0.4 sodium ascorbic acid (Sigma-Aldrich), 2 MgSO₄ (Sigma-Aldrich), 1 CaCl₂ (Sigma-Aldrich), and 1 MgCl₂ (Sigma-Aldrich). A mid-sagittal cut was made to divide the two hemispheres, and coronal brain slices (300 μm) were cut using a vibrating blade microtome (Leica VT1200). The brain slices were transferred to a holding chamber with oxygenated artificial CSF (ACSF) containing (in mM): 119 NaCl (Sigma-Aldrich), 2.5 KCl (Fisher Chemical), 1 NaH₂PO₄ (Sigma-Aldrich), 26.2 NaHCO₃ (Sigma-Aldrich), 11 D-glucose (Sigma-Aldrich), 1 sodium ascorbic acid (Sigma-Aldrich), 1.3 MgSO₄ (Sigma-Aldrich), and 2.5 CaCl₂ (Sigma-Aldrich; ∼295 mOsm, pH 7.2–7.3) at 37°C for 20 min and then room temperature for at least 40 min of rest. The slices were kept submerged in oxygenated ACSF in a holding chamber at room temperature for up to 7–8 h after slicing.