Functional ultrasound assessment of cerebral blood flow and brain connectivity in a pilocarpine-induced acute epileptic seizures in mice.

BACKGROUND

Temporal lobe epilepsy (TLE) is one of the most prevalent pharmaco-resistant epilepsies in adults, for which no effective curative regimens or disease-modifying therapies are currently available. Studies have shown that cerebral blood volume (CBV) is significantly reduced throughout the whole brain in epileptic patients during the interictal period, while some have reported increased local cerebral blood flow (CBF). These findings indicate that during epileptic seizures, there are changes in the blood flow of the brain. However, for TLE, the changes in brain blood flow and the functional connections of related nuclei remain unclear.

METHODS

The present study aimed to use functional ultrasound imaging (fUS) to detect changes in CBV in mice during acute seizure state of TLE, as well as alterations in global brain functional network connectivity.

RESULTS

Our findings showed that most brain regions exhibit changes in relative CBV (rCBV). Among the 12 epilepsy-related brain regions, all except the intermediodorsal nucleus of the thalamus (IMD) and striatum (STR) showed an initial increase followed by a decrease in rCBV. Additionally, the rCBV changes in the reticular nucleus of the thalamus (RT) occurred earlier than in other nuclei, the brain's functional connectivity (FC) underwent distinct changes, which may be associated with the remodeling of brain FC.

CONCLUSION

These results demonstrated that CBV exhibited heterogeneous changes across the whole brain, and the overall brain functional network connectivity underwent modifications during acute seizure state of TLE in mice.