MDA receptors (NMDAR) are ligand-gated ion channels that play a crucial role in several forms of synaptic plasticity, learning and memory, and neural development. These receptors mediate excitatory synaptic transmission and are implicated in numerous neurological disorders. NMDARs are heterotetramers typically composed of two NR1 subunits and two NR2 subunits (NR2A and NR2B). Most of the functional and pharmacological properties of NMDARs arise from the NR2 subunit composition of the receptor. Growing evidence suggests that Neuroligin 1 (NL-1), a trans-synaptic cell adhesion molecule involved in excitatory synapse formation and maturation, may play a role in modulating NMDAR function at mature synapses, but the mechanisms underlying such modulation are poorly understood. Recently, our group has identified a form of long-term potentiation (LTP) of NMDAR transmission at the mossy fiber (mf) to CA3 pyramidal cell synapse in the hippocampus (NMDAR-mfLTP), and we are currently investigating the cellular and molecular mechanisms involved in this plasticity. Specifically we are studying whether NL-1 could have a role in NMDAR-mfLTP. To this end, I am monitoring NMDAR-mediated synaptic responses using extracellular and whole-cell recordings in acute hippocampal slices from wild-type (WT) and NL1 knock-out (KO) mice.