Hippocampal ensemble dynamics and memory performance are modulated by respiration during encoding.

Area of Science:

• Neuroscience
• Respiratory Physiology
• Memory Research

Background:

• Respiration coordinates hippocampal activity during offline states like sleep.
• The role of breathing in online memory encoding is not well understood.

Purpose of the Study:

• To investigate the role of respiration in online memory encoding.
• To determine if respiratory activity influences hippocampal dynamics during memory formation.

Main Methods:

• Used optogenetic manipulation to control the PreBötzinger complex (PreBötC), the brain's respiratory rhythm generator, in mice.
• Induced intermittent apnea (cessation of breathing) during object exploration and fear conditioning tasks.
• Recorded changes in CA3 cell ensembles in the hippocampus.

Main Results:

• Intermittent PreBötC-induced apnea during object exploration impaired novel object detection.
• Apnea during fear memory encoding prevented freezing behavior in response to conditioned stimuli (CS+).
• Apnea blocked the dynamic changes in hippocampal CA3 cell ensembles typically seen with CS+ stimuli.

Conclusions:

• Central respiratory activity, including breathing frequency, is recruited during online memory encoding.
• Breathing dynamics significantly shape hippocampal ensemble activity and memory performance during learning.
• These findings highlight a novel link between respiratory control and cognitive processes.