Pharmacologic MRI in Cocaine Addiction

An extensive effort has been mounted to understand the neurobiologic mechanisms involved in
the development and persistence of cocaine addiction and tendency to relapse. Although the
last two decades have resulted in an explosion in our understanding of the biological
mechanisms of reward, establishing the relevance of this knowledge to the addictive process
has been problematic. Most importantly, this information has been of limited utility in
offering new pharmacologic treatment approaches to addicted patients - particularly those
with cocaine addiction. Over the past 15 years our laboratory has published multiple studies
using pharmacologic probes to explore the biologic underpinnings of cocaine addiction using
single photon emissions computerized tomography (SPECT) technology. More recently, however,
functional magnetic resonance imaging (fMRI) has offered several advantages over SPECT and
is now a favored approach, e.g. fMRI allows the continuous measurement of neural responses
rather than a very limited time period with SPECT (1-3 minutes every 48 hours). Using fMRI
[including both ASL (Arterial Spin Labeling) and fcMRI (functional connectivity], the neural
response can be measured throughout the 60 min that follows infusion, allowing
identification and capture of the maximal brain response period that may occur at any time
during this 60 min. In the proposed study, we will assess the brain response to two of the
probes (scopolamine and lidocaine) we have previously studied with SPECT.

Inclusion Criteria:

- Cocaine dependence (cocaine patients)

- identify cocaine as their present primary drug of use

- Patients must have used cocaine within the previous 4 weeks (by patient history) and
be abstinent for at least 1 week.

- No drug dependence (healthy control population).

Exclusion Criteria:

- Other medical or psychiatric disorders that may effect neural functioning.

- Medications that may effect brain functioning