Physiology of Human Brain Connectivity
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 入组人数
- 80
- 试验地点
- 2
- 主要终点
- Changes in EEG effective connectivity
研究概览
简要总结
The purpose of this study is to investigate the effective connectivity between different regions of the human brain in healthy participants, and the mechanisms which influence and modulate its development. Specifically, the investigators will examine the effects of cortico-cortical paired associative stimulation (ccPAS) which is induced by the application of brief (< 1 ms) transcranial magnetic stimulation (TMS) pulses separated by a short millisecond-level time intervals ("asynchrony") to two different areas of the brain. All techniques are non-invasive and considered safe in humans: TMS, electroencephalography (EEG), and magnetic resonance imaging (MRI). Based on previous animal and human studies, it is hypothesized that ccPAS will increase or decrease effective connectivity between the stimulated areas depending on the asynchrony value. The main outcome measure is source-resolved EEG cortico-cortical evoked potentials (ccEPs) elicited by single-pulse TMS.
详细描述
The purpose of this study is to determine the extent to which effective connectivity between different regions in the human brain can be selectively modulated by cortico-cortical paired associative stimulation (ccPAS) induced by transcranial magnetic stimulation (TMS). Study subjects will consist of healthy adults between the ages of 18 and 64 (N=80) . Participants will have TMS pulses applied to two brain regions, one in each hemisphere, where the two regions will be stimulated at a range of different temporal offsets ("asynchronies") characterized as being either shorter, longer, or approximately equal to the theorized inter-regional conduction delays, with absolute disparities between the asynchrony conditions on the order of milliseconds. Additionally, electroencephalography (EEG) will be concurrently measured to record cortico-cortical evoked potentials (ccEPs), which are the study's primary outcome measure. Asynchronies longer than the delay are hypothesized to increase effective connectivity and ccEP amplitudes, while shorter delays are expected to decrease them. This will be further supported by magnetic resonance imaging (MRI), functional MRI (fMRI), and diffusion MRI (dMRI) scans to provide structural and functional data to assist with ccPAS application.
The initial study visit will consist of the MRI scans followed by a TMS session to record participant motor thresholds. The ccPAS TMS-EEG procedures will then be performed over the course of three additional visits, with each asynchrony condition conducted on its own separate visit and at least a week between them. Prior to ccPAS application, single-pulse TMS will be applied to one brain area to record ccEPs, in addition to resting-state EEG and a behavioral motor test. These will be repeated two additional times, once 5 minutes after ccPAS and again at 60 minutes after, to observe effect duration. All techniques and devices are non-invasive and considered safe within the parameters of the study, with overall participation carrying only non-significant risk.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Basic Science
- 盲法
- None
盲法说明
Participants will not be informed of the asynchrony value for each visit. The order of asynchronies is randomized.
入排标准
- 年龄范围
- 18 Years 至 64 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Age from 18 to 64 years
- •Right-handed
- •Normal hearing and (corrected) vision
- •Able to understand and give informed consent
排除标准
- •Cardiac pacemaker or pacemaker wires; neurostimulators; implanted pumps
- •Metal in the body (e.g., rods, plates, screws, shrapnel, dentures that cannot be removed during the recordings, IUD)
- •Suspected metallic particles in the eye
- •Surgical clips in the head or previous neurosurgery
- •Any magnetic particles in the body
- •Cochlear implants
- •Prosthetic heart valves
- •Epilepsy or any other type of seizure history
- •Any neurological diagnoses or medications influencing brain function
- •History of significant head trauma (i.e., extended loss of consciousness, neurological sequelae)
- •Known structural brain lesion
- •Significant other disease (heart disease, malignant tumors, mental disorders)
- •Significant claustrophobia; Ménière's disease
- •Pregnancy (ruled out by urine ß-HCG if answers to screening questions suggest that pregnancy is possible), breast feeding
- •Non prescribed drug use
- •Failure to perform the behavioral tasks or neuropsychological evaluation tests
- •Prisoners
结局指标
主要结局
Changes in EEG effective connectivity
时间窗: Within-session (Before PAS, 5 minutes after PAS, 60 minutes after PAS)
EEG will be recorded with a 64-channel whole-head TMS-compatible device (NeurOne 64, Bittium, Kuopio, Finland). Data will be collected before (Pre) and at 5 minutes (Post-1) and at 60 minutes (Post-2) after PAS. To record spTMS-evoked EEG responses the investigators will deliver 80 single TMS pulses to the two areas receiving PAS, one target after the other in separate runs. Effective connectivity will be measured by comparing the source-resolved EEG evoked response waveforms before (Pre) and at 5 (Post-1) and at 60 minutes after PAS (Post-2).
次要结局
- Changes in resting-state EEG coherence(Within-session (Before PAS, 5 minutes after PAS, 60 minutes after PAS))
- Changes in bimanual coordination task performance(Within-session (Before PAS, 5 minutes after PAS, 60 minutes after PAS))
研究者
Tommi A. Raij
Principal Investigator
Massachusetts General Hospital