The role that PSD organization plays in synaptic function and plasticity is only beginning to be understood. AMPARs play a well-established role in LTP; up-regulation of AMPARs within the postsynaptic density (PSD) is generally accepted to be the primary mechanism of NMDAR-dependent LTP. The function that AIDA-1 (Amyloid-[beta] protein precursor intracellular domain-associated protein-1), a recently discovered component of the PSD, plays within synapses is less clear; however, in cultured hippocampal neurons, a portion of AIDA-1 translocates to the nucleus and increases downstream protein translation in response to NMDAR activation, Thus, experimental evidence suggests a role for AIDA-1 in synapse-to-nucleus signaling during NMDAR activation. My project uses electron microscopy and other histological techniques to determine the basal organization of AMPARs and AIDA-1 within the PSD. These data may provide better understanding of the roles these proteins play.