← Explore

Low-Intensity Transcranial Ultrasound Stimulation Inhibits Epileptic Seizures in Motor Cortex by Modulating Hippocampus Neural Activity

Na Pang, Qianqian Wang, Jiamin Pei, Hailin Zhang, Yi Yuan, Jiaqing Yan

IEEE Transactions on Neural Systems and Rehabilitation Engineering 2025 · 10.1109/tnsre.2025.3525516

rodentepilepsyinvasive electrophysiologyhistology molecular

Abstract

Prior studies indicate that applying low-intensity transcranial ultrasound stimulation (TUS) to the hippocampus can suppress epileptic seizures. Nevertheless, it is unclear how TUS regulates hippocampal neural activity, and whether and how epileptic discharges in the motor cortex are suppressed by modulating hippocampal neural activity. To explore the answers of above questions, ultrasound was utilized to investigate the responses to the aforementioned inquiries by stimulating the hippocampus of mice with penicillin-induced epilepsy, while simultaneously recording the local field potentials (LFPs) in the hippocampus and the motor cortex (M1) throughout the experiment. The results showed that TUS (1) reduced the amplitude and the strength of the θ frequency band in LFPs in the hippocampus and M1, (2) decreased the coupling strength of the δ-γ, θ-γ and α-γ frequency bands in the hippocampus and M1, (3) weakened the correlation of neural activity between the hippocampus and M1. The above results indicated that TUS effectively suppressed abnormal slow neural oscillations in the hippocampus, had a significant decoupling effect on slow-fast neural oscillations, and reduced the correlation of hippocampus-cortical neural activity. TUS of the hippocampus may be through the hippocampus-cortical circuits to suppress abnormal neural firing activity in M1.

Abstract via europepmc.

Speciesmouse (C57BL/6)
Subjects10, 10swept animals
Sessions per subjectnot reported
Randomisedyes
Blindingnot reported
Sham / controlinactive transducer
Auditory controlnot reported
Readout timingboth
Anaesthesianot reported
Readoutsinvasive electrophysiology, histology molecular — LFP in hippocampal CA3 and M1 (power, phase-amplitude coupling, cross-correlation); H&E staining
Direction of effectinhibitoryTUS of the hippocampus reduced theta-band amplitude and power, phase-amplitude coupling and hippocampus-M1 correlation of LFPs in penicillin-induced epileptic mice.
Adverse eventsnone observedH&E staining indicated TUS caused no damage to brain tissue (Supplementary Figure 1).

Exposures

Exposure 1: TUS of hippocampus

Target: hippocampus — “hippocampus”
Device: Olympus / Panametrics · Olympus · V302-SU ✓

Pulse timing
Waveformpulsed
Fundamental frequency (kHz)1,000✓✓✓
Pulse duration (ms)1✓✓✓
Pulse repetition frequency (Hz)500✓✓✓
Duty cycle (%)50pulse duration × PRF gives 50%✓✓✓
Sonication duration (s)900✓✓✓⚑
Pressure and intensity, by domain
Free-field pressure (kPa)not reported
Free-field Isppa (W/cm²)not reported
Free-field Ispta (W/cm²)not reported
In-situ estimatenot reported
In-situ pressure (kPa)not reported
In-situ Isppa (W/cm²)not reported
In-situ Ispta (W/cm²)not reported
Pressure, domain unspecified (kPa)330✓✓✓⚑
Protocol, in the paper’s words

Fundamental frequency 1 MHz, PRF 500 Hz, duty cycle 50%, pulse duration 1 ms, inter-stimulus interval 1 ms, total stimulation duration 15 min, 0.33 MPa, applied 40 min after penicillin injection. Sham: power amplifier turned off.

Flags from extraction

  • exposures[0].unspecified_domain.pressure_kpa — Pressure 0.33 MPa stated without saying whether free-field or in situ.
  • exposures[0].timing.sonication_duration_s — Paper states 'total stimulation duration' of 15 min; recorded as 900 s.
  • n_subjects — Only group sizes given (10 TUS, 10 sham); recorded as list.