Early hippocampal high-amplitude rhythmic spikes predict post-traumatic epilepsy in mice

Area of Science:

• Neuroscience
• Brain Injury Research
• Epilepsy Pathophysiology

Background:

• Brain oscillations are crucial for mammalian brain function and are implicated in neurological disorders.
• Traumatic brain injury (TBI) frequently causes lasting changes in brain activity, increasing the risk of complications like post-traumatic epilepsy (PTE).
• Understanding early TBI-induced oscillatory changes is key to predicting and potentially preventing PTE.

Approach:

• Longitudinal local field potential recordings were performed in the hippocampus of 12 Collaborative Cross (CC) mouse strains and C57BL/6J mice post-TBI.
• Acute (<12 hr) and subacute (12-48 hr) hippocampal oscillatory responses to TBI were analyzed.
• The predictive value of these early oscillatory alterations for PTE development was evaluated.

Key Points:

• CC031 mice that later developed PTE exhibited distinct acute-phase hippocampal oscillations characterized by high-amplitude rhythmic spikes, increased power density, and reduced entropy.
• These specific early oscillatory patterns were not observed in sham-operated CC031 mice or in other mouse strains that did not develop PTE.
• The findings establish a quantitative link between early-stage brain oscillations and PTE development at a population level.

Conclusions:

• Early detection of specific hippocampal oscillatory signatures following TBI can predict PTE development in susceptible individuals.
• These findings provide crucial insights into the neural circuit mechanisms underlying TBI-induced epilepsy.
• The identified early biomarkers may serve as targets for future neuromodulatory interventions aimed at preventing PTE.