There are three major subtypes of ionotropic glutamate receptors: NMDA, AMPA, and kainate-type (KA-R). While we are beginning to understand the effects of alcohol on BLA AMPA and NMDA receptors, very little is known about the effects of alcohol exposure on kainate-type glutamate receptors. These receptors are structurally similar to the better-studied AMPA-type glutamate receptors and are typically found in both pre- and postsynaptic compartments throughout the forebrain (Jin et al., 2006; Weiner et al., 1999; West et al., 2007). Functional KA-Rs can consist of five potential subunit combinations: GLUR5–7 are needed for functional channels; the KA1–2 subunits confer unique pharmacological and biophysical properties to the native receptor (Braga et al., 2004). GLUR5,6 and KA2 subunits are highly expressed in the BLA; and, kainate receptors contribute to glutamatergic excitatory postsynaptic potentials (EPSPs) in this brain region (Li and Rogawski, 1998).
