5'-alkyl-benzothiadiazides: a new subgroup of AMPA receptor modulators with improved affinity.

AMPA receptors form a major subdivision of the glutamate receptor family that mediates excitatory synaptic transmission in the brain. Currents through AMPA receptors can be up- or down-regulated by compounds that allosterically modulate receptor kinetics through binding sites distinct from that for glutamate. One of those modulators is the benzothiadiazide IDRA-21 which has been reported to enhance synaptic transmission and be effective in behavioral tests, but typically requires threshold concentrations of at least 100 microM to be active in vitro.