Modulating amygdala activation to traumatic memories with a single ketamine infusion
medRxiv Preprint Server – July 07, 2021
Source: medRxiv
Summary
Imagine being able to rewrite distressing memories. Research explored whether a single ketamine infusion, an NMDA receptor antagonist, could help modulate the fear response associated with trauma memories. By activating memories, then administering ketamine, the study aimed to enhance their extinction during reconsolidation. Findings showed ketamine recipients had reduced amygdala and hippocampus activity to trauma memories, suggesting improved extinction learning. This remarkable approach successfully modulated fear responses for at least 30 days, offering a promising path to alter traumatic memories.
Abstract
NMDA receptor antagonists have a vital role in extinction, learning, and reconsolidation processes. During the reconsolidation window, memories are activated into a labile state and can be stored in an altered form. This concept might have significant clinical implications in treating PTSD. Using amygdala activity as a major biomarker of fear response, we tested the potential of a single subanesthetic intravenous infusion of ketamine (NMDA receptor antagonist) to enhance post-retrieval extinction of PTSD trauma memories. Post-extinction, ketamine recipients (vs midazolam) showed a lower amygdala and hippocampus reactivation to trauma memories. Post-retrieval ketamine administration was also associated with decreased connectivity between the amygdala and hippocampus, with no change in amygdala-vmPFC connectivity, which suggests that ketamine may enhance post-retrieval extinction of PTSD trauma memory in humans. These findings demonstrate the capacity to rewrite human traumatic memories and to modulate the fear response for at least 30 days post-extinction.