Imaging the Neuroimmune Dynamics Across Space and Time

Area of Science:

• Neuroimmunology
• Neuroscience
• Cell Biology

Background:

• Immune cells, particularly microglia, are vital for brain homeostasis, growth, and repair.
• Studying these cells is challenging due to their sensitivity to microenvironmental changes.
• Non-invasive imaging has revolutionized the understanding of immune cell roles in the brain.

Purpose of the Study:

• To review current and emerging imaging techniques for studying brain immune cells.
• To highlight methods for increasing spatial and temporal resolution in neuroimmune imaging.
• To discuss the translational potential of imaging modalities for microglia and macrophages.

Main Methods:

• Two-photon in vivo microscopy for microglial dynamics.
• High-resolution electron microscopy (including 3D reconstruction) for synaptic interactions.
• Super-resolution fluorescence microscopy.
• Serial block-face scanning electron microscopy for nanoscale 3D reconstruction.
• Positron emission tomography (PET) with functional radiotracers.
• Magnetic resonance imaging (MRI).

Main Results:

• Two-photon microscopy revealed microglial interactions with neurons, astrocytes, blood vessels, and synapses.
• Advanced microscopy elucidated microglial roles in synaptic processes like phagocytosis and trogocytosis.
• Serial block-face scanning electron microscopy provided nanoscale 3D reconstructions of microglia.
• PET and MRI show promise for translational research between animal models and humans.

Conclusions:

• A diverse array of imaging techniques enables detailed study of brain immune cells.
• Emerging methods promise enhanced resolution for neuroimmune imaging.
• PET and MRI offer significant potential for clinical translation in studying neuroinflammation.