Hello, May I suggest that you use NBQX which has 2 main advantages 1. Soluble in water at 1mM concentration 2. More selective AMPA receptors antagonist (CNQX at > 10 uM concentration is a week NMDA antagonist You could get it from Tocris Cookson, UH, Fax +44 1934 853435 Hope it will help Etienne Pralong epralong at iphysiol.unil.ch