Noninvasive Ultrasound Deep Brain Stimulation for the Treatment of Parkinson’s Disease Model Mouse

Hui Zhou, Lili Niu, Long Meng, Zhengrong Lin, Junjie Zou, Xiangxiang Xia, Xiaowei Huang, Wei Zhou, Tianyuan Bian, Hairong Zheng

Research 2019, 2019 · 10.34133/2019/1748489

rodentparkinsons diseasebehaviourhistology molecular

Abstract

Modulating basal ganglia circuitry is of great significance in the improvement of motor function in Parkinson's disease (PD). Here, for the first time, we demonstrate that noninvasive ultrasound deep brain stimulation (UDBS) of the subthalamic nucleus (STN) or the globus pallidus (GP) improves motor behavior in a subacute mouse model of PD induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Immunohistochemical c-Fos protein expression confirms that there is a relatively high level of c-Fos expression in the STN-UDBS and GP-UDBS group compared with sham group (both p < 0.05). Furthermore, STN-UDBS or GP-UDBS significantly increases the latency to fall in the rotarod test on day 9 (p < 0.05) and decreases the time spent climbing down a vertical rod in the pole test on day 12 (p < 0.05). Moreover, our results reveal that STN-UDBS or GP-UDBS protects the dopamine (DA) neurons from MPTP neurotoxicity by downregulating Bax (p < 0.001), upregulating Bcl-2 (p < 0.01), blocking cytochrome c (Cyt C) release from mitochondria (p < 0.05), and reducing cleaved-caspase 3 activity (p < 0.01) in the ipsilateral substantia nigra (SN). Additionally, the safety of ultrasound stimulation is characterized by hematoxylin and eosin (HE) and Nissl staining; no hemorrhage or tissue damage is detected. These data demonstrate that UDBS enables modulation of STN or GP neural activity and leads to neuroprotection in PD mice, potentially serving as a noninvasive strategy for the clinical treatment of PD.

Abstract via europepmc.

Speciesmouse (C57BL/6J)

Subjectsnot reported animals

Sessions per subject7

Randomisedyes

Blindingnot reported

Sham / controlinactive transducer, active control site

Auditory controlnot reported

Readout timingoffline

Anaesthesiaawake

Readoutsbehaviour, histology molecular — rotarod test; pole test; open field test; c-Fos immunohistochemistry; TH immunohistochemistry; western blot (Bcl-2, Bax, Cyt C, cleaved-caspase 3); HE and Nissl staining

Direction of effectexcitatorySTN-UDBS or GP-UDBS increased c-Fos-positive neurons in the STN/GP versus sham, improved rotarod and pole-test performance versus MPTP-sham, and protected TH-positive neurons and reduced apoptotic markers versus MPTP-sham; ultrasound to control target V1 had little effect on pole-test performance.

Adverse eventsnone observedHematoxylin and eosin (HE) and Nissl staining showed no hemorrhage or tissue damage in STN-UDBS or GP-UDBS groups after seven days of stimulation; mechanical index (0.17) and Ispta (180 mW/cm2) were below FDA diagnostic ultrasound imaging thresholds.

Exposures

Exposure 1: STN-UDBS

Target: subthalamic nucleus — “subthalamic nucleus (STN)”
Device: custom-built

Pulse timing
Waveform	pulsed
Fundamental frequency (kHz)	3,800	✓✓✓
Pulse duration (ms)	0.5	✓✓✓
Pulse repetition frequency (Hz)	1,000	✓✓✓
Duty cycle (%)	50pulse duration × PRF gives 50%	✓✓✓
Sonication duration (s)	1	✓✓✓

Pressure and intensity, by domain
Free-field pressure (kPa)	190	✓✓✓
Free-field Isppa (W/cm²)	not reported
Free-field Ispta (W/cm²)	0.43	✓✓✓
In-situ estimate	measurementsingle value
In-situ pressure (kPa)	100	✓✓✓
In-situ Isppa (W/cm²)	not reported
In-situ Ispta (W/cm²)	0.18	✓✓✓

Protocol, in the paper’s words

4 s inter-stimulation interval (ISI) between 1 s sonications, delivered 30 min per day for a total of 7 days (day 6-12), applied transcranially to freely moving, awake mice via a wearable single-element transducer guided by a skull-mounted collimator.

Exposure 2: GP-UDBS

Target: globus pallidus — “globus pallidus (GP)”
Device: custom-built

Pulse timing
Waveform	pulsed
Fundamental frequency (kHz)	3,800	✓✓✓
Pulse duration (ms)	0.5	✓✓✓
Pulse repetition frequency (Hz)	1,000	✓✓✓
Duty cycle (%)	50pulse duration × PRF gives 50%	✓✓✓
Sonication duration (s)	1	✓✓✓

Pressure and intensity, by domain
Free-field pressure (kPa)	190	✓✓✓
Free-field Isppa (W/cm²)	not reported
Free-field Ispta (W/cm²)	0.43	✓✓✓
In-situ estimate	measurementsingle value
In-situ pressure (kPa)	100	✓✓✓
In-situ Isppa (W/cm²)	not reported
In-situ Ispta (W/cm²)	0.18	✓✓✓

Protocol, in the paper’s words

Flags from extraction

n_subjects — Paper states a total of 120 mice used across the whole study but different sub-experiments (behaviour, IHC, western blot, SOD, safety histology) each use different subsets with different n; no single total for animals exposed to ultrasound is given.
sham_type — Groups I/II sham involved wearing an inactive (powered-off) transducer (inactive_transducer); a separate supplementary experiment stimulated V1 with real ultrasound as a control target (active_control_site).