Fear memory-triggered sleep disruption: insights from ventral hippocampus-basolateral amygdala manipulation

Area of Science:

• Neuroscience
• Sleep Science
• Memory Research

Background:

• Daytime fear experiences can disrupt sleep, but the neural mechanisms are not fully understood.
• The ventral CA1-basolateral amygdala (vCA1-BLA) pathway's role in fear-related sleep alterations requires investigation.

Purpose of the Study:

• To investigate how fear memory influences sleep patterns.
• To examine the contribution of the vCA1-BLA pathway to sleep changes associated with fear recall.

Main Methods:

• Experiments conducted on adult male mice.
• Fear conditioning followed by auditory stimuli presentation during sleep.
• Utilized calcium imaging, optogenetics, local field potential, chemogenetics, and activity-dependent genetic labeling tools (ADGLT).

Main Results:

• Enhanced vCA1-BLA pathway activity observed during sleep with fear-conditioned auditory stimuli in a fear-associated context.
• Inhibition of the vCA1-BLA pathway reduced sleep-to-wake transitions upon re-exposure to fear cues.
• Increased information flow from vCA1 to BLA during tone-triggered sleep-wake transitions; re-stimulation of activated vCA1➔BLA neurons increased sleep disruptions and freezing behavior.

Conclusions:

• The vCA1-BLA circuit's heightened activity correlates with disrupted sleep continuity during fear recall.
• Fear-associated neural ensembles can reactivate during sleep, potentially causing sleep disturbances.
• Identified a neural mechanism linking fear memory to sleep disruption.