The MEMOPROSTHETICS project focuses on advancing our understanding of learning and memory, and the potential for neurostimulation to enhance cognitive functions in non-human primates with and without cognitive impairments. In a first objective, we investigate the neural oscillations (electrical signals that oscillate at specific frequencies and are characteristic of a particular brain area and and / neurological function) that mediate learning and memory in three brain areas: the hippocampus, entorhinal cortex, and prefrontal cortex. To this end, we first developed custom brain implants for precise neural recordings and stimulation, as well as methods based on magnetic resonance imaging and optical tracking for targeting these areas with a submillimetric precision. Our preliminary results have identified changes in neural signals that are correlated with a memory task. In our next objectives, we examine whether electrical stimulation of these areas, so-called deep brain stimulation (DBS), can enhance or disrupt the creation of new memories. While applying stimulation parameters that had been previously used in patients with epilepsy, we have found that stimulating the hippocampus or the entorhinal cortex at certain amplitudes deteriorates memory performance. We are now exploring various stimulation parameters to understand conflicting results in the existing literature and develop robust protocols for improving memory. These objectives are conducted both in a state without cognitive deficits, and in a state where temporary cognitive impairments are induced by a pharmacological intervention. Finally, our last objective will attempt to miniaturize our current system to make it fully implantable and pave the way to future clinical studies. Overall, the project integrates innovative technologies to explore the intricate relationship between stimulation parameters, neural activity, and learning and memory processes, with implications for treating neurological disorders such as Alzheimer’s disease.
