Hippocampal sharp wave-ripple dynamics in NREM sleep encode motivation for anticipated physical activity

Area of Science:

• Neuroscience
• Behavioral Biology
• Physiology

Background:

• Physical activity is crucial for mammal survival and fitness, requiring integrated body-brain coordination.
• Motivation for exercise stems from survival needs or the rewarding nature of the activity itself.
• Hippocampal sharp wave-ripples (SWRs) are involved in cognitive and metabolic functions, potentially aiding body-brain coordination.

Approach:

• Monitored hippocampal CA1 SWRs and running behaviors in mice during voluntary wheel running.
• Manipulated the incentive salience of the running experience to study exercise motivation.
• Analyzed correlations between SWR dynamics (duration, cell assembly activation, inter-ripple intervals, and rates) and running behavior.

Key Points:

• During non-REM sleep before exercise, SWR duration positively correlated with future running duration.
• Larger pyramidal cell assemblies were activated during longer SWRs, indicating SWRs encode exercise motivation.
• SWR dynamics during sleep before exercise correlate with subsequent physical activity levels.

Conclusions:

• Hippocampal CA1 SWRs play a novel role in encoding motivation for physical activity.
• SWRs support cognitive and metabolic functions that motivate behavior by coordinating the body and brain.
• This research sheds light on the neural substrates underlying internally generated motivation for exercise.