Low-intensity transcranial focused ultrasound engages parvalbumin-positive GABAergic interneurons in a humanized mouse model of chronic pain: from electrophysiology to cellular investigation
Min Gon Kim, Chih-Yu Yeh, Huan Gao, Keunhyung Lee, Kalpna Gupta, Bin He
Journal of Neural Engineering 2026 · 10.1088/1741-2552/ae54cd
Abstract
Objective. Low-intensity transcranial focused ultrasound (tFUS) offers high spatial specificity and deep brain penetration, representing a promising non-invasive approach for modulating brain activity and behavior. Although emerging studies indicate that tFUS can modulate pain-related behaviors in rodents and humans, the underlying network-level and cellular mechanisms remain unknown. This study investigates the effects of tFUS neuromodulation on inhibitory neural circuits in a humanized mouse model of chronic pain, integrating electrophysiological, molecular, and histological analyses across a cohort of 50 animals, including wild-type controls. Approach. A 128-element random array transducer was used to precisely target the pain-processing brain circuit, while a non-invasive and flexible 30-channel electroencephalography electrode was applied to record local evoked responses, topographical activity, and global excitation and inhibition dynamics, which were further validated by optogenetics experiments. Cellular-level modulation and safety outcomes were evaluated through blinded histological examination. Main results. We found that tFUS produced robust modulation of local and global brain activity, characterized by suppression of local theta oscillations and enhancement of network-level inhibitory dynamics. These electrophysiological patterns aligned with those observed during optogenetic activation of parvalbumin (PV) interneurons. Immunohistochemistry further showed significant increases in inhibitory neuronal markers, including elevated expressions of glutamate decarboxylase 67 and PV. Blinded histological assessment confirmed the absence of tissue damage, supporting the safety of the stimulation paradigm. Significance. These findings demonstrated that tFUS stimulation non-invasively engages PV GABAergic inhibitory circuits in a chronic pain mouse model, providing mechanistic insight and supporting its development as a precise and safe neuromodulation technology for clinical translation.
Abstract via europepmc.
Exposures
Exposure 1: tFUS to S1HL, PRF 40 Hz or 3 kHz, single- and multi-session
Target: primary somatosensory cortex — “hindlimb region of the primary somatosensory cortex (S1HL)”
Device: Sonic Concepts · Sonic Concepts, Inc. · H276 128-element random array ✓
| Waveform | pulsed | |
|---|---|---|
| Fundamental frequency (kHz) | 1,500 | ✓✓✓ |
| Pulse duration (ms) | 0.2 | ✓✓✓ |
| Pulse repetition frequency (Hz) | 40, 3,000swept | ✓✓✓ |
| Duty cycle (%) | 0.8, 60swept | ✓✓✓⚑ |
| Sonication duration (s) | 0.1, 0.4swept | ✓✓✓⚑ |
| Free-field pressure (kPa) | not reported | |
|---|---|---|
| Free-field Isppa (W/cm²) | not reported | |
| Free-field Ispta (W/cm²) | not reported | |
| In-situ estimate | measurementsingle value | |
| In-situ pressure (kPa) | 45.2 | ✓✓✓⚑ |
| In-situ Isppa (W/cm²) | 0.35 | ✓✓✓ |
| In-situ Ispta (W/cm²) | 0.00202, 0.208swept | ✓✓✓⚑ |
Single session: TBD 200 us, PRF 40 Hz or 3 kHz, UD 100 ms, ISoI 2 s, 20 min total (600 sonications). Multi-session (40 Hz only): UD 400 ms, ISoI 4 s, 1 h per day for 14 d.
Consistency checks: intensity pressure inconsistent in situ.
Flags from extraction
exposures[0].in_situ.pressure_kpa— Text gives peak negative pressure 45.2 kPa; Table 1 column 'In situ pressure (kPa)' gives 90.4. Text value recorded.exposures[0].in_situ.ispta_w_cm2— Paper gives 2.02 and 208.46 mW/cm2; converted to W/cm2 (0.00202, 0.20846).exposures[0].in_situ.method— Measured through a freshly excised mouse skull in a water tank; recorded as in_situ measurement.exposures[0].timing.duty_cycle_pct— Duty cycles (0.8 and 60) and the 400 ms multi-session UD appear only in Table 1; 40 Hz goes with 0.8 % and 3 kHz with 60 %.exposures[0].timing.sonication_duration_s— UD is 100 ms for single-session and 400 ms for multi-session (Table 1).n_subjects— 50 animals stated in abstract; analysed groups were 17 SCD, 8 wild-type, 5 multi-session, plus 8 rats for optogenetics without ultrasound.sham_type— Negative control / sham-treated groups are mentioned but how produced is not described.randomised— Only the order of conditions in within-subject experiments is stated as randomised.blinding— Only histology scoring was blinded; stimulation blinding not stated.