In previous studies the carboxyl-terminus of microtubule-associated protein 1S was shown to interact with the N-methyl-D-aspartate receptor subunit NR3A (Eriksson et. al.)1. In this study, interactions between three truncations of the microtubule-associated proteins 1B and one truncation of the microtubule-associated protein 1S carboxyl-terminus and the N-methyl-D-aspartate receptor subunits NR1 and NR3A were examined. The study showed that an interaction occurred between amino acids 2167 to 2365 of the microtubule-associated protein 1B and NR3A. That region of microtubule associated protein 1B corresponds to a microtubule-binding region in the light chain. It has been shown in earlier studies (Reviewed in Halpain S. et a12, Riederer, BM. et.al3.) that the light chain is a active part of the protein that have been post translational cleaved. The MAP 1 proteins are present in all tissue but has higher concentrations in the Post Synaptic Density of neurons in the central nervous system. The N-methyl-D-aspartate receptors are present in glial cells and in the dendritic shafts of the central nervous system neurons (Eriksson et. al.)1 . The diseases were these proteins may play a part is mainly memory destructive diseases such as Alzheimers disease and in muscular dystrophy, but these assumptions are still being speculated.