Functional imaging of the human dopaminergic midbrain

Trends Neurosci. 2009 Jun;32(6):321-8. doi: 10.1016/j.tins.2009.02.005. Epub 2009 May 14.

Abstract

Invasive recording of dopamine neurons in the substantia nigra and ventral tegmental area (SN/VTA) of behaving animals suggests a role for these neurons in reward learning and novelty processing. In humans, functional magnetic resonance imaging (fMRI) is currently the only non-invasive event-related method to measure SN/VTA activity, but it is debated to what extent fMRI enables inference about dopaminergic responses within the SN/VTA. We consider the anatomical and functional parcellation of the primate SN/VTA and find that its homogeneity suggests little variation in the regional specificity of fMRI signals for reward-related dopaminergic responses. Hence, these responses seem to be well captured by the compound fMRI signal from the SN/VTA, which seems quantitatively related to dopamine release in positron emission tomography (PET). We outline how systematic investigation of the functional parcellation of the SN/VTA in animals, new developments in fMRI analysis and combined PET-fMRI studies can narrow the gap between fMRI and dopaminergic neurotransmission.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Behavior, Animal / physiology
  • Brain Mapping / methods
  • Dopamine / metabolism*
  • Haplorhini
  • Humans
  • Magnetic Resonance Imaging / methods
  • Neural Pathways / anatomy & histology
  • Neural Pathways / physiology
  • Neurons / metabolism
  • Neurons / physiology
  • Papio
  • Positron-Emission Tomography / methods*
  • Rats
  • Substantia Nigra / anatomy & histology
  • Substantia Nigra / diagnostic imaging*
  • Substantia Nigra / physiology
  • Synaptic Transmission
  • Ventral Tegmental Area / anatomy & histology
  • Ventral Tegmental Area / diagnostic imaging*
  • Ventral Tegmental Area / physiology

Substances

  • Dopamine