Engram engineering and false memories - Ramirez's research

The article analyzes a breakthrough in memory research conducted at the Tonegawa Lab at MIT, where the transition from observation to causal control over the engram changed the foundations of neuroscience. Thanks to the work of Steve Ramirez and Xu Liu using optogenetics and genetic systems (including the c-Fos promoter), scientists were able to selectively tag neurons active during specific experiences and subsequently stimulate them artificially. These experiments proved that the reactivation of a specific ensemble of cells is sufficient to trigger behavior corresponding to a given memory, even in a safe environment. This approach combines molecular genetics with experimental psychology, treating memory not as a metaphysical record, but as a measurable and controllable biological system.