8 cyclopentyltheophylline 8 cpt

Drug solutions were prepared fresh at the start of each experiment to prevent degradation by environmental factors e.g. light. Solutions were made using de-ionized water (pH 5–6, resistance 18.2 MΩcm) from a Milli-Q UV plus system.
ChTX was dissolved in water and stored in small aliquots at −20°C. It was then dissolved to its final concentration of 10 nM. The sodium channel blocker, tetrodotoxin (TTX, 1 μM), was used to block initiation and propagation of action potentials. The selective A1 –receptor antagonist, 8-cyclopentyltheophylline (8-CPT; Sigma, St. Louis, MO), was initially dissolved in DMSO and subsequently in ACSF to give a final concentration of 10 μM.
Bis-(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid acetoxymethyl ester (BAPTA-AM) and EGTA-AM (Molecular Probes, Eugene, OR) were initially dissolved in DMSO, and then diluted to their final concentrations in the ACSF. DMSO concentration in ACSF was 0.0001% for 1 μM BAPTA-AM and 0.00006% for 50 μM of EGTA-AM. The chelator freely entered the cell due to the AM moiety and was then deesterified to cell-impermeant BAPTA. Probenecid (Sigma, St. Louis, MO) was dissolved in 1 M NaOH and subsequently buffered with HCl acid to pH 7.4. Whenever Probenecid was used (1 mM) care was taken to adjust the sodium concentration of the ACSF. Probenecid and DMSO did alone did not alter fEPSP at concentrations used.

SNE was prepared as 20 mg/ml stock solution in an appropriate artificial cerebrospinal fluid (aCSF, composition described below), centrifuged at 1,792 g (relative centrifugal force) for 10 min, the supernatant collected, aliquoted and stored frozen at −20°C. 8-cyclopentyltheophylline (8-CPT) (Sigma-Aldrich, Poole, Dorset, United Kingdom) was prepared as 2 mm stock solutions and frozen until use. On the day of use, the stock solutions were thawed, and aliquots diluted with aCSF to the desired concentrations. Each stock preparation was used within 2 weeks and any remnants were discarded.