Neonatal Sleep Restriction Increases Nociceptive Sensitivity in Adolescent Mice

Area of Science:

• Neuroscience
• Developmental Biology
• Sleep Science

Background:

• Infant sleep loss may negatively impact the developing nociceptive system.
• Neonatal sleep restriction is hypothesized to cause long-term increases in pain behaviors and alter nociceptive pathway neuronal activity.

Purpose of the Study:

• Investigate the long-term effects of neonatal sleep loss on pain behaviors in adolescent and adult mice, considering sex differences.
• Analyze neuroanatomical and functional changes in pain pathways related to observed behavioral alterations.

Main Methods:

• Neonatal mice (postnatal day 12) underwent sleep restriction (SR) or maternal separation (MS) for 10 days.
• Pain behaviors were assessed at postnatal days 21, 35, and 90.
• Immunohistochemistry for c-Fos protein was performed in key brain regions, including the periaqueductal gray (PAG).

Main Results:

• Neonatal SR significantly increased nociceptive sensitivity in adolescent mice (hot plate test).
• This hypersensitivity correlated with decreased c-Fos expression in the PAG.
• Pain hypersensitivity was absent in adult mice, indicating a transient effect.

Conclusions:

• Repeated early-life sleep loss can alter nociceptive responses.
• These changes are associated with modifications in the neural activity of descending pain control pathways.
• The findings highlight the critical role of early sleep in pain system development.