NMDA receptors involvement in memory and prediction

Memory and prediction are fundamental cognitive functions shaping our daily activities, with prediction enhancing the likelihood of successful action and relying heavily on memory. Studies indicate that spike timing-dependent plasticity (STDP), a mechanism altering synaptic weights based on temporal coordination, is crucial for memory, with NMDA activation playing a pivotal role. Our investigation aimed to assess the impact of inhibiting NMDA activation on long-term memory and prediction in random in-vitro networks of dissociated rat cortical neurons using MEAs.
During long-term memory formation, experiences are initially encoded in the hippocampus and later reactivated, triggering neocortical areas in systems consolidation. To study memory and prediction, we subjected cultures to focal, low-frequency electrical stimulation. For memory, a 10 min stimulation with 1 h intervals of spontaneous activity was employed. For prediction, 20 h focal stimulation with random interstimulus intervals..., , , # NMDA receptors involvement in memory and prediction

Our goal was to answer the following questions: given the important role of spike timing dependent plasticity in memory, and the role played by NMDA receptors in STDP, which effects would have blocking NMDA receptors activation on memory consolidation, and consequently on long-term memory? And also, given the recently proven ability of cultured neural networks to predict upcoming stimuli, would, blockage of these receptors, have an effect also on prediction? To answer these questions we applied focal electrical stimulation through one electrode to networks plated on micro electrodes array (MEAs), undergoing control conditions or transfected with APV (an NMDA antagonist).

Stimulation protocol for memory: acquisition of 1h spontaneous activity (Baseline), followed by focal electrical stimulation at 2 different electrodes (A and B). Per each electrode we applied 5 stimulation periods of 10min (0.2Hz) interspersed by 1h spontaneous act...