Effects of Nicotine and Attention on Frequency Tuning in Auditory Cortex
试验速览
- 阶段
- 1 期
- 状态
- 已完成
- 入组人数
- 44
- 试验地点
- 1
- 主要终点
- frequency tuning of excitatory auditory fMRI cortical responses
研究概览
简要总结
Nicotine enhances auditory-cognitive function because it mimics the brain's system for "paying attention" to important sounds amid distractions (for example, understanding speech in a noisy environment). In part, nicotine does this by activating inhibitory neurons in the auditory cortex. Since age-related hearing deficits result, in part, from the loss of inhibitory neurons in auditory cortex, this project will determine whether nicotine's effects can compensate for reduced inhibition in the aging auditory cortex and thereby restore auditory function.
The investigators will use functional magnetic resonance imaging (fMRI) to measure the selectivity of responses in auditory cortex to tones of various frequencies. The investigators will measure the effects of nicotine (administered as chewing gum) and aging on these fMRI response properties. The investigators hypothesize that frequency selectivity will decrease with aging and increase following nicotine administration.
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
- Triple (Participant, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 18 Years 至 85 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •non-smokers with a score of 0-2 out of 10 maximum on the Fagerström index of smoking dependency
排除标准
- •deafness or excessive hearing loss
- •smokers with a score between 3 and 10 on the Fagerström index of smoking dependency
- •history of psychiatric illness, neurological disorders, diabetes mellitus, renal failure, or cardiovascular disease
- •regular use of prescription medications (excluding oral contraceptives)
- •drug dependency
研究组 & 干预措施
Young (18-28 years) participants - nicotine gum
6 mg nicotine gum, one time before fMRI measurements
干预措施: Nicotine gum (Drug)
Old (60-85 years) participants - nicotine gum
6 mg nicotine gum, one time before fMRI measurements
干预措施: Nicotine gum (Drug)
Young (18-28 years) participants - placebo gum
placebo gum, one time before fMRI measurements
干预措施: Placebo gum (Other)
Old (60-85 years) participants - placebo gum
placebo gum, one time before fMRI measurements
干预措施: Placebo gum (Other)
结局指标
主要结局
frequency tuning of excitatory auditory fMRI cortical responses
时间窗: Functional MRI recordings will begin approximately 30 minutes after oral administration of polacrilex or placebo gum and will continue for up to two hours.
Functional magnetic resonance imaging (fMRI) responses to pure tone stimuli ranging from 88-8000 Hz will be recorded. For each voxel in objectively identified auditory cortical area, a tuning curve model will be fit to the data. One of the parameters of this model is the width of frequency tuning of excitatory responses, and this is the primary outcome measure.
次要结局
- frequency tuning of inhibitory auditory fMRI cortical responses(Functional MRI recordings will begin approximately 30 minutes after oral administration of polacrilex or placebo gum and will continue for up to two hours.)
- amplitude of excitatory auditory fMRI cortical responses(Functional MRI recordings will begin approximately 30 minutes after oral administration of polacrilex or placebo gum and will continue for up to two hours.)
- amplitude of inhibitory auditory fMRI cortical responses(Functional MRI recordings will begin approximately 30 minutes after oral administration of polacrilex or placebo gum and will continue for up to two hours.)