Neuroplastic Alterations of the Motor Cortex by Caffeine: Differences Between Caffeine and Non-caffeine Users and Influence of Vigilance During Stimulation
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 30
- 试验地点
- 2
- 主要终点
- The influence of vigilance during stimulation
研究概览
简要总结
Caffeine is a psychostimulant drug. It acts as a competitive antagonist at adenosine receptors, which modulate cortical excitability as well. In deep brain stimulation (DBS), the production of adenosine following the release of adenosine triphosphate (ATP) explains the reduction of tremor. Binding of adenosine to adenosine A1 receptors suppresses excitatory transmission in the thalamus and hereby reduces both tremor-and DBS-induced side effects. Also, the effect of adenosine was attenuated following the administration of the 8-Cyclopentyl-1,3-dipropylxanthine (DPCPX) adenosine A1 receptor antagonist. Therefore, the presence of a receptor antagonist such as caffeine was suggested to reduce the effectiveness of deep brain stimulation (DBS) in treating tremor and other movement disorders.
Based on this finding, the investigators hypothesize that the antagonistic effect of caffeine can tentatively block the excitatory effects of transcranial alternating current stimulation (tACS). The plasticity effects might differ among caffeine users and non- caffeine users depending on the availability of receptor binding sites.
Apart from that, a major issue in NIBS studies including those studying motor-evoked potentials is the response variability both within and between individuals. The trial to trial variability of motor evoked potentials (MEPs) may be affected by many factors. Inherent to caffeine is its effect on vigilance. In this study, the investigator shall monitor the participant's vigilance by pupillometry to (1) better understand the factors, which might cause variability in transcranial excitability induction studies and (2) to separate the direct pharmacological effect from the indirect attentional effect of caffeine.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- Double (Participant, Investigator)
盲法说明
A statistician prepares a randomization list. Only the pharmacist knows the medication type (caffeine or placebo) and the type of electrical stimulation. The researcher knows only the vigilance conditions (**passive or *active) . An investigator is blinded to the type of electrical stimulation and medication. In addition, all participants are naive to electrical stimulation and do not know if they receive placebo or verum drug.
入排标准
- 年龄范围
- 18 Years 至 45 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Male and female healthy participants between the ages of 18-
- •Right-handed (Oldfield 1971).
- •Free willing participation and written, informed consent of all subjects obtained prior to the start of the study.
- •Participant's weight is above 60 kg
排除标准
- •Age < 18 or > 45 years old;
- •Left hand dominant;
- •Evidence of a chronic disease or history with a disorder of the nervous system
- •History of epileptic seizures;
- •Pacemaker or deep brain stimulation;
- •Metal implants in the head region (metal used in the head region, for example, clips after the operation of an intracerebral aneurysm (vessel sacking in the region of the brain vessels), implantation of an artificial auditory canal);
- •Cerebral trauma with loss of consciousness in prehistory;
- •Existence of a serious internal (internal organs) or psychiatric (mental illness)
- •Alcohol, medication or drug addiction;
- •Receptive or global aphasia (disturbance of speech comprehension or additionally of speech);
- •Participation in another scientific or clinical study within the last 4 weeks;
- •Breastfeeding
- •Intolerance to caffeine or coffee products
- •Participant who has abnormal heart activity from an electrocardiography (ECG) finding
- •Weight is less than 60 kg
结局指标
主要结局
The influence of vigilance during stimulation
时间窗: 10 minutes
Participant's level of vigilance is monitored from pupil diameter and pupil unrest index (PUI) using pupillometer. This measurement is carried out during 10 minutes of transcranial alternating current stimulation (tACS)
Neuroplastic changes of the cortical areas
时间窗: Baseline (pre-measurement), immediately after intervention, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes
Motor cortex plasticity is measured from the changes in the amplitude of the motor evoked potentials (MEPs) at different time points. Transcranial magnetic stimulation (TMS) will be used to measure MEP amplitudes.
次要结局
- Genetic polymorphism(1 year)
研究者
Prof. Dr. Walter Paulus
Head of Department for Clinical Neurophysiology
University Medical Center Goettingen