Neuronal ensembles that hold specific memories (memory engrams), are defined as enduring physical and/or chemical change in a neural network that is the result of neuronal activation by episodic stimuli [1] Engram cells have been identified in multiple brain regions, including the hippocampus, amygdala, thalamus, and cortex It has been hypothesized that these distributed engrams are functionally connected [2] This neural network can be specifically reactivated, resulting in the recall of the original memory [3]However, how the interaction among multiple regions facilitates the consolidation, or long-term storage, of memory remains unknown.Here, we will investigate the role of hippocampal thalamic cortical coordination in memory consolidation Combining transgenic mice and optogenetics, we will examine the physiological signature of thalamic engrams By inhibiting them using chemogenetics during consolidation, we will investigate the role of thalamic engram cells in the recent and remote recall Using optogenetic manipulation and in vivo multi region recordings via dual Neuropixels 2.0 4-shank probes, we would examine the effect of manipulation of thalamic engram on hippocampal and cortical engrams, and how they are coupled during events underlying memory consolidation. Reference[1]Tonegawa , Nat. Rev. Neurosci 2018.[2] Takamiyaet, S. et al. Neuroscience Research, 2019.[3] Liu et al.,Nature ,2012