3-Bromo-7-nitroindazole is a potent and selective neuronal nitric oxide synthase (nNOS) inhibitor (1,2). It is also a neuroprotective compound that inhibits the endoplasmic reticulum stress pathway. 3-Bromo-7-nitroindazole has been used to study the role of nitric oxide synthase (nNOS) in spatial memory formation in rats (2).