LY404187 is a benzothiadiazide positive allosteric modulator of AMPA receptors.1 It increases glutamate-induced activation of GluR1i, -2i, -2o, -3i, and -4i subunit-containing AMPA receptors with EC50 values of 5.65, 0.15, 1.44, 1.66, and 0.21 μM, respectively, in a calcium influx assay. LY404187 is selective for these AMPA receptors over GluR6 subunit-containing kainate receptors at 10 μM. LY404187 increases currents induced by glutamate and AMPA in rat prefrontal cortex pyramidal neurons (EC50s = 1.3 and 1.2 μM, respectively) but not in AMPA-stimulated primary rat embryonic hippocampal or primary cerebellar Purkinje neurons.2,3 LY404187 prevents decreases in the number of dopaminergic neurons in the substantia nigra induced by MPTP and 6-OHDA in mouse and rat, respectively, models of Parkinson's disease when administered at a dose of 0.5 mg/kg per day.4

|1. Miu, P., Jarvie, K.R., Radhakrishnan, V., et al. Novel AMPA receptor potentiators LY392098 and LY404187: Effects on recombinant human AMPA receptors in vitro. Neuropharmacology 40(8), 976-983 (2001).|2. Baumbarger, P.J., Muhlhauser, M., Zhai, J., et al. Positive modulation of α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors in prefrontal cortical pyramidal neurons by a novel allosteric potentiator. J. Pharmacol. Exp. Ther. 298(1), 86-102 (2001).|3. Gates, M., Ogden, A., and Bleakman, D. Pharmacological effects of AMPA receptor potentiators LY392098 and LY404187 on rat neuronal AMPA receptors in vitro. Neuropharmacology 40(8), 984-991 (2001).|4. O'Neill, M.J., Murray, T.K., Whalley, K., et al. Neurotrophic actions of the novel AMPA receptor potentiator, LY404187, in rodent models of Parkinson's disease. Eur. J. Pharmacol. 486(2), 163-174 (2004).