Experimental Psychology Seminar - Ralitsa Todorova

Abstract: Memory formation is often described as a two-step process.  First, the hippocampus rapidly encodes new experiences, forming transient memory traces. During subsequent sleep, these traces are stabilised and integrated into long-term memory through systems consolidation. 

 In this talk, I will present the two complementary codes in the hippocampus that can encode memory trace. These include an associative code, which links related elements of an experience through cell assemblies, and a predictive code, which captures the temporal structure of events through neuronal sequences. We leveraged an optogenetic approach in freely moving rats that can dissociate these two coding schemes, and provide evidence that they have different memory functions.  

 In the second part of the talk, I will focus on the reactivation of these memory traces during hippocampal ripples in sleep. While ripples broadcast memory-related information throughout the brain, not all ripples have the same impact. Our recent findings show that large ripples are the ones that engage reactivation in the prefrontal cortex, and boosting ripples enhances memory consolidation.

Zoom Link: https://ucl.zoom.us/j/91372041706?pwd=uQfxoFubMh2x66Bb3gt2Hfgb6Ye8hk.1 
Meeting ID: 913 7204 1706
Passcode: 105540