Investigating NMDA Receptor Contributions to Postsynaptic Potentials, Synaptic Integration and Hippocampal Network Dynamics

N-Methyl-D-Aspartate (NMDA) receptors, play a critical role in synaptic plasticity and are linked to various neurological disorders. Recent advancements in genetic sequencing have identified numerous variants in the GRIN2A gene, encoding the NMDAR receptor subunit GluN2A, to be associated with severe clinical outcomes, including intellectual disability, epileptic encephalopathy, speech and language impairments, and psychiatric illness. Yet, the specific mechanisms underlying the pathophysiology in these conditions remains elusive. Effective neuronal communication hinges on the precise coordination of synaptic signals. Conventionally, it is believed that the slow decay of NMDA receptor-mediated excitatory postsynaptic currents (EPSCs), is crucial for temporal summation and synaptic integration. However, my preliminary evidence from a Grin2a-depleted rat model challenges this view, suggesting that NMDA receptors do not contribute to the excitatory post synaptic potentials (EPSPs) of hippocampal pyramidal cells under physiological conditions. As such, this project seeks to further explore the impact of GluN2A depletion on temporal summation in inhibitory hippocampal cell populations. I will combine advanced electrophysiological techniques with ex vivo calcium imaging to assess how channel kinetics influence neuronal function, circuit plasticity and hippocampal network dynamics. Through this research, I aim to deepen our understanding of synaptic function, NMDA receptor physiology and the role of GluN2 subunit-conferred kinetics in neuronal computation and the sculpting of hippocampal network dynamics. By improving our understanding of how GRIN2A variants induce synaptic and network dysfunction, this research aims to provide novel insights into the pathogenesis of GRIN2A-associated disorders and identify novel targets for future development of targeted therapeutic interventions to improve the quality of life for affected individuals.