Preinspiratory calcium rise in putative pre-Botzinger complex astrocytes

Area of Science:

• Neuroscience
• Respiratory Physiology
• Astrocyte Biology

Background:

• Respiratory rhythm generation is primarily attributed to neuronal networks in the pre-Bötzinger complex (preBötC).
• The role of astrocytes, non-neuronal cells, in central respiratory control is an emerging area of research.
• The precise mechanisms of respiratory rhythmogenesis remain incompletely understood.

Purpose of the Study:

• To investigate the potential role of astrocytes in the pre-Bötzinger complex (preBötC) in respiratory rhythm generation.
• To determine if astrocyte activity precedes or coincides with neuronal activity during respiratory rhythmogenesis.

Main Methods:

• Functional calcium imaging of hundreds of cells within the preBötC in rhythmically active brain slices.
• Utilized tetrodotoxin to block neuronal activity and assess astrocyte rhythmicity.
• Employed optogenetic stimulation of preBötC astrocytes to observe effects on neuronal firing.

Main Results:

• A subset of putative astrocytes in the preBötC exhibited rhythmic intracellular calcium elevations preceding inspiratory neuronal firing by approximately 2 seconds.
• These astrocyte rhythms persisted during tetrodotoxin-induced neuronal blockade, though frequency decreased and intercellular coupling was reduced.
• Optogenetic activation of preBötC astrocytes successfully induced inspiratory neuronal firing.

Conclusions:

• Astrocytes within the preBötC display rhythmic activity that precedes and can influence neuronal inspiratory activity.
• These findings suggest a potentially active and significant role for astrocytes in the generation of respiratory rhythms.
• Further research is warranted to elucidate the precise molecular and circuit mechanisms of astrocyte involvement in respiratory control.