Cocaine administration decreases functional connectivity in human primary visual and motor cortex as detected by functional MRI

Magn Reson Med. 2000 Jan;43(1):45-51. doi: 10.1002/(sici)1522-2594(200001)43:1<45::aid-mrm6>;2-0.


Functional magnetic resonance imaging (fMRI) was conducted to observe the effects of cocaine administration on the physiological fluctuations of fMRI signal in two brain regions. Seven long-term cocaine users with an average age of 32 years and 8 years of cocaine use history were recruited for the study. A T2*-weighted fast echo-planar imaging (EPI) pulse sequence was employed at 1.5 T to acquire three sets of brain images for each subject under three conditions (at rest, after saline injection, and after cocaine injection [0.57 mg/kg]). Cross-correlation maps were constructed using the synchronous, low frequency signal from voxel time courses after filtering respiratory, cardiac, and other physiological noise. A quantitative evaluation of the changes in functional connectivity was made using spatial correlation coefficient (SCC) analysis. A marked 50% reduction in SCC values in the region of primary visual cortex and 43% reduction in SCC values in the region of primary motor cortex were observed after cocaine administration. This significant reduction in SCC values in these cortical regions is a reflection of changes in neuronal activity. It is suggested that the observed changes in low frequency components after acute cocaine administration during a resting, no-task situation may be used as a baseline reference source when assessing the effects of cocaine on task-driven activation or on mesolimbic dopamine pathways.

Publication types

  • Clinical Trial
  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Cocaine / administration & dosage*
  • Echo-Planar Imaging / methods*
  • Humans
  • Magnetic Resonance Imaging*
  • Male
  • Motor Cortex / drug effects*
  • Motor Cortex / pathology
  • Reference Values
  • Sensitivity and Specificity
  • Sodium Chloride / administration & dosage
  • Substance-Related Disorders / diagnosis
  • Substance-Related Disorders / physiopathology*
  • Synaptic Transmission / drug effects*
  • Visual Cortex / drug effects*
  • Visual Cortex / pathology


  • Sodium Chloride
  • Cocaine