Molecular brain imaging of psychedelic action

Area of Science:

• Neuroscience
• Radiology

Background:

• Molecular brain imaging, including Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT), visualizes in vivo brain processes like perfusion and metabolism, as well as molecular targets such as neuroreceptors.
• These imaging techniques, developed in the 1980s, were initially applied to study psychostimulant drugs.

Purpose of the Study:

• To review the current literature on molecular brain imaging of psychedelic action.
• To highlight the need for broader and systematic investigation of psychedelic effects on brain function, particularly given their emerging therapeutic potential.

Main Methods:

• Review of published literature focusing on SPECT studies of cerebral perfusion and PET studies of metabolism and neuroreceptors.
• Analysis of studies investigating psychedelic interactions with neuroreceptors, primarily serotonin 5-HT2A receptors, and to a lesser extent, dopamine D2/3 receptors.

Main Results:

• The use of molecular imaging in psychedelic research has grown in the past decade, though the literature remains limited.
• Most studies focus on PET imaging of serotonin 5-HT2A receptors, which are key to psychedelic effects, and some studies document interactions with dopamine D2/3 receptors.

Conclusions:

• Molecular brain imaging provides valuable insights into the mechanisms of psychedelic action.
• Further research is needed to systematically investigate the effects of psychedelics on various brain targets and functions, especially for their potential therapeutic applications in neurological and psychiatric disorders.