An optogenetic approach to study memory in vitro

Investigating the processes that underly memory formation in the brain can be a difficult task. Conventional in vivo experiments involve millions of different cells whose processes are difficult to be isolated and singularly studied. This is where in vitro techniques can offer a controlled environment to examine the mechanisms involved in the operation of the basic circuits involved in memory (engrams). We developed a technique that combines digital light processing (DLP) with Optogenetics to achieve precise control over neuronal activity. We were able to generate small, discrete modules of engram circuits in vitro that adhere to Hebb's postulate. By utilizing the Synactive labeling technique alongside our strategy, we were able to identify and track strengthened spines between active neurons. This enabled us to examine how a pattern of activity between neurons is established within the engram circuits, which are also known as synaptic engrams. This method can be used to create more precise experimental models of memory storage and retrieval, opening the doors to a new understanding of the processes underlying brain activity.