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Completed

NCT Number: NCT05018117

Effects of Nicotine and Attention on Frequency Tuning in Auditory Cortex

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.

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Key information

Conditions

Aging

Age range

18 year–85 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Early Phase 1

Primary location

University of California, Berkeley

Berkeley, California, 94720, United States

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • non-smokers with a score of 0-2 out of 10 maximum on the Fagerström index of smoking dependency

Exclusion criteria

  • 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

Treatment and study plan

Nicotine gum

Drug

The effects of over-the-counter nicotine gum will be compared to a placebo gum

Other names: polacrilex

Placebo gum

Other

The effects of over-the-counter nicotine gum will be compared to a placebo gum

Primary outcomes

  1. frequency tuning of excitatory auditory fMRI cortical responses

    Time frame: 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.

Secondary outcomes

  1. frequency tuning of inhibitory auditory fMRI cortical responses

    Time frame: 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 inhibitory responses, and this is Outcome 2.

  2. amplitude of excitatory auditory fMRI cortical responses

    Time frame: 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 amplitude of excitatory responses, and this is Outcome 3.

  3. amplitude of inhibitory auditory fMRI cortical responses

    Time frame: 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 amplitude of inhibitory responses, and this is Outcome 4.

Sponsors and collaborators

Lead sponsor

University of California, Berkeley

Other

Collaborators

  • National Institute on Aging (NIA)

Registry information

Important dates

Study start
2022
Primary completion
2025
Study completion
2025
First posted
Aug 24, 2021
Registry last updated
Jul 24, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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