Ttx citrate

Pharmacological agents were purchased from: Sigma-Aldrich: Fluoroacetate, thapsigargin, BAPTA, bicuculline methbromide, Tricine, Zinc chloride, d-serine, and GDPβS; Tocris Bioscience: nimodipine, (+)-MK-801 maleate, d-AP5, NBQX, TTX citrate, PPDA, Ro 25-6981 maleate, MCPG, MPEP, LY341495, AM251, 2-AG, and FK506; and Abcam: UBP-141. Salts used for internal and external solutions were purchased from Sigma-Aldrich. Compounds were dissolved in H₂O or Ringer solution with the exception of thapsigargin, nimodipine, PPDA, FK506, THL, AM251, and 2-AG, which were dissolved in DMSO. Vehicle (DMSO) at the concentrations used did not affect baseline EPSP amplitudes and had no other detectable effects on the neurons. When investigating the effect of pharmacological agents on plasticity, all drugs were included in the superfusion fluid or patch pipette from the start of the experiment until completion (from 0 to 50 min in a standard plasticity experiment), except for Fluoroacetate, which was applied from 60 min before the start of recording. When determining the effect of a pharmacological agent on baseline condition, a stable baseline of at least 10 min was first recorded and then the drug was bath applied by switching to a different perfusion line.

AMPAR-mediated mEPSCs were isolated by voltage-clamping neurons at −70 mV and by supplementing the ACSF with TTX citrate (1 μM, Abcam), the GABA (A) receptor antagonist picrotoxin (50 μM, Sigma-aldrich), and the NMDA receptor antagonist D, L-2-amino-5 phosphonopentanoic acid (100 μM, AP5, Abcam)^{62 (link)}. The internal solution contained: 100 mM CsCH₃SO₃, 15 mM CsCl, 2.5 mM MgCl₂, 5 mM QX-314-Cl, 5 mM tetra-Cs-BAPTA, 10 mM HEPES, 4 mM Mg-ATP, 0.3 mM Na-GTP, and 0.5% (w/v) neurobiotin with pH adjusted to 7.25 with 1 M CsOH and osmolarity adjusted to ~295 mOsm with sucrose.

AP5, Bicuculline methiodide (BIM), CGP 55845, picrotoxin, NBQX, and TTX citrate were purchased from Abcam, isoflurane from Abbott, and 5α-THDOC and all other substances/salts from Sigma-Aldrich. Drugs were applied by bath application.