A gut-secreted peptide suppresses arousability from sleep.

Area of Science:

• Neuroscience
• Sleep Science
• Animal Physiology

Background:

• Sleep requires effective sensory suppression to prevent arousal.
• Mechanisms underlying sensory gating during sleep are not fully understood.
• Dietary factors may influence sleep-related sensory processing.

Purpose of the Study:

• To investigate the role of diet, specifically protein intake, in modulating sensory suppression during sleep.
• To elucidate the signaling pathway by which dietary information influences arousal thresholds.
• To determine if this effect is specific to certain sensory modalities.

Main Methods:

• Experiments were conducted on sleeping flies and mice.
• Responsiveness to mechanical vibrations was measured under varying dietary protein levels.
• A signaling pathway involving enteroendocrine cells, CCHa1 peptide, and dopamine neurons was identified in flies.

Main Results:

• Higher dietary protein intake significantly improved suppression of responsiveness to mechanical vibrations in both flies and mice.
• A gut-brain signaling pathway was identified in flies: dietary protein increases CCHa1 peptide release, which modulates dopamine neuron activity to reduce vibration responsiveness.
• This protein-dependent suppression mechanism was specific to vibration stimuli, not affecting all sensory inputs.

Conclusions:

• Dietary protein content plays a crucial role in regulating sensory gating during sleep.
• A novel gut-brain-neuronal pathway (protein-gut-CCHa1-dopamine) mediates enhanced sensory suppression during sleep.
• Sleep involves independent gating mechanisms for different sensory information streams.