Nicotinic Modulation of the Default Network

Magnetic Resonance Imaging Clinical Trial

Official title:

Nicotinic Modulation of the Default Network of Resting Brain Function

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01223404
• Other study ID #: HP-00042696
• Secondary ID: R21DA027894
• Status: Completed
• Phase: N/A
• Start date: October 2010
• Est. completion date: September 2013

Study information

• Verified date: August 2019
• Source: University of Maryland, Baltimore
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Many disorders where attentional problems are a hallmark, such as Alzheimer's disease and schizophrenia, display abnormal regulation of the so-called default network of resting brain function that maintains internally directed thought when the mind is free to wander. There is indication that nicotine may improve attention by aiding the deactivation of the default network, and this mechanism may be of therapeutic benefit for the above disease states. The current project aims at providing a proof of concept by demonstrating that nicotinic drugs modulate default network function. The nicotinic agonist nicotine is hypothesized to improve attention by facilitating the down-regulation of default network activity, and the nicotinic antagonist mecamylamine is hypothesized to impair attention by impeding the down-regulation of default network activity during attentional task performance.

Description:

This study only enrolls healthy non-smokers. Participants perform attention tasks while undergoing functional Magnetic Resonance Imaging on three separate days. Across the three days, three difference conditions are tested in a double-blind manner, in randomized order. In all test sessions, participants receive a skin patch and swallow a capsule. In one session, both are a placebo. In another, the patch is a low-dose nicotine patch, and the capsule is a placebo. In another session, the patch is a placebo and the capsule contains a low dose of mecamylamine.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 21
• Est. completion date: September 2013
• Est. primary completion date: September 2013
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 21 Years to 50 Years

Eligibility

Inclusion Criteria:

• Age 21 through 50.

• Did not consume cigarettes, cigarillos, cigars, or other tobacco or nicotine-containing products more than 20 times in lifetime, and did not use any nicotine-containing product at all within the last two years.

• Normal or corrected to normal vision (at least 20/80).

Exclusion Criteria:

• Presence of metal objects in the body, implanted electronic devices, or any other counter indication for MRI.

• Claustrophobia.

• Major psychiatric disorders including mood, anxiety or psychotic disorders.

• Cardiovascular or cerebrovascular disease, such as history of myocardial infarction, heart failure, angina, stroke, severe arrhythmias, or EKG abnormalities.

• Kidney or liver disease.

• Hypertension (resting systolic BP above 140 or diastolic above 85 mm Hg).

• Hypotension (resting systolic BP below 95 or diastolic below 60).

• Use of any prescription or over-the-counter drug other than supplements and birth control.

• History of or current neurological illnesses, such as stroke, seizures, dementia or organic brain syndrome.

• Learning disability, attention deficit disorder, or any other condition that impedes memory and attention.

• Glaucoma, organic pyloric stenosis, uremia or renal insufficiency.

• Prostatic hypertrophy, bladder neck obstruction or urethral stricture.

• Left-handed or ambidextrous.

• Pregnant as determined by urine test, or breast-feeding.

• History or current diagnosis of drug or alcohol abuse or dependence.

• IQ < 85 as estimated by the WASI vocabulary subtest.

Related Conditions & MeSH terms

• Cognition
• Magnetic Resonance Imaging
• Mecamylamine
• Nicotine

Intervention

Drug:
• Placebo
Participants are administered a placebo patch and a placebo capsule
• Nicotine
Participants are administered a nicotine patch (7 mg/24 hrs) and a placebo capsule
• Mecamylamine
Participants are administered a placebo patch and a capsule containing 7.5 mg of mecamylamine

Locations

Country	Name	City	State
United States	Maryland Psychiatric Research Center	Baltimore	Maryland
United States	National Institute on Drug Abuse, Intramural Research Program	Baltimore	Maryland

Sponsors (2)

Lead Sponsor	Collaborator
University of Maryland, Baltimore	National Institute on Drug Abuse (NIDA)

Country where clinical trial is conducted

United States, 

References & Publications (1)

Hahn B, Ross TJ, Yang Y, Kim I, Huestis MA, Stein EA. Nicotine enhances visuospatial attention by deactivating areas of the resting brain default network. J Neurosci. 2007 Mar 28;27(13):3477-89. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Reaction Time	average reaction time on cognitive task performed in the MR scanner	1 day
Primary	Signal Detection Performance	Signal detection on cognitive tasks performed in the MR scanner. For the attention task, this represents the percentage of trials in which the participant responded when a signal was presented. In the working memory task (N-back task), this represents the percentage of all target sequences to which the participant responded.	1 day
Primary	Default Network Activity	Cognitive task-induced default network deactivation, measured by functional Magnetic Resonance Imaging. The default network was probed by five pre-defined ROIs per hemisphere. Task-induced deactivation was averaged across all ROIs.	1 day
Secondary	Subjective State	End-of-session subjective state is measured by the Profile of Mood States (POMS). We utilize "Total Mood Disturbance" (TMD) as a summary measure, derived by adding the total scores on the five negative mood scales (tension, depression, anger, fatigue, confusion) and subtracting the score on the one positive mood scale (vigor). The theoretical range of the TMD scale is -32 to 228, with negative values indicating less mood disturbance, i.e., a more positive emotional state.	1 day
Secondary	Systolic Blood Pressure	Systolic blood pressure (mmHg)	Bi-hourly: prior to patch application, 2 hours, 4 hours, and 6 hours after, and after the MRI scan (~8 hours after patch application)
Secondary	Diastolic Blood Pressure	Diastolic blood pressure in mmHg.	Bi-hourly: prior to patch application, 2 hours, 4 hours, and 6 hours after, and after the MRI scan (~8 hours after patch application).