Artificially modulating memories to combat psychiatric disease-like states

Summary

Date: 
October 27, 2015 - 12:00pm
Location: 
NW 243
About the Speaker
Name: 
Steve Ramirez (MIT)

Memories thread and unify our overall sense of being. With the accumulation of our knowledge about how memories are encoded, consolidated, retrieved, and updated, neuroscience has reached a point where brain cells active during these discrete mnemonic processes can be identified and manipulated at rapid timescales. Here, I begin with historical studies that lead to the modern memory engram theory. Then, I present our recent advances in memory research that combine transgenic, optogenetic, and various imaging approaches to reveal underlying neuronal substrates sufficient for activating mnemonic processes. Our studies’ conclusions are threefold: (1) we provide proof of principle evidence demonstrating that learning-related neural changes can be isolated at the level of single cells, and that these cells can then be tagged for subsequent modulation; (2) a defined subset of hippocampus cells are sufficient to elicit the neuronal and behavioral expression of memory recall, as well as sufficient to modify existing positive and negative memories; (3) and finally, artificially activated memories can be leveraged to acutely and chronically suppress psychiatric disease-related states. I propose that hippocampus cells that show activity-dependent changes during learning construct a cellular basis for contextual memory engrams and that directly activating these endogenous neuronal processes can be an effective means to correct maladaptive behaviors.