NBQX (FG9202)

NBQX is highly selective in vitro. The IC50 value for inhibition of AMPA-evoked inward currents is 0.4 μM for NBQX. While NBQX inhibits NMDA-induced currents with IC50 value of 60 μM.^[2]

Cells are continuously superfused with extracellular saline at a rate of 2.5 ml/min. After giga-seal formation the whole cell configuration is obtained by suction.The holding potential is - 60 mV and at the start of each experiment the current is measured continuously for 30 s to ensure a stable baseline. Agonist-containing solutions are delivered to the chamber through a custom-made gravity-driven flowpipe, the tip of which is placed approximately 50 μm from the cell. Application is triggered when the tubing connected to the flowpipe is compressed by a valve controlled by the Pulse software. In general, agonists are applied for 1.5 or 3 s every 45 s. The sample interval during application is 600 μs. After stable responses are obtained, the extracellular saline as well as the agonist-containing solution are replaced by solutions containing NBQX to be tested. NBQX is present until responses of a repeatable amplitude are achieved. Currents are measured at the plateau phase of the responses just before deactivation.

Rats are intraperitoneally (i.p.) injected with pentylenetetrazole (PTZ, 50 mg/kg) for 28 consecutive days to establish chronic epilepsy models. Subsequently, NBQX (20 mg/kg, i.p.) is injected for 3 days for the observation of behavioral measurements of epilepsy. NBQX treatment normalizes perineuronal nets (PNNs), tenascin-R, aggrecan and neurocan levels. NBQX is sufficient to decrease seizures through increasing the latency to seizures, decrease the duration of seizure onset, and reduce the scores for the severity of seizures.^[1]