Neuronal activity increases translocator protein (TSPO) levels.

Area of Science:

• Neuroscience
• Molecular Biology
• Cell Biology

Background:

• Translocator protein (TSPO) is a biomarker for neuroinflammation.
• TSPO's cellular expression is not selective, suggesting broader functions.
• Investigating TSPO's role in neuronal activity is crucial.

Purpose of the Study:

• To determine if neuronal activity influences TSPO levels in the adult central nervous system.
• To characterize TSPO expression patterns in different cell types.

Main Methods:

• Single-cell RNA sequencing of mouse hippocampus.
• Confocal laser scanning microscopy.
• Stimulation of neuronal activity via DREADDs, novel environment exposure, and amphetamine treatment.

Main Results:

• TSPO is expressed in neurons, astrocytes, microglia, and vascular cells.
• Neuronal activity consistently increased TSPO mRNA and protein in neurons.
• TSPO levels did not increase in microglia or astrocytes following neuronal stimulation.

Conclusions:

• Neuronal activity modulates TSPO levels in the adult brain.
• Altered TSPO expression may not always indicate neuroinflammation.
• Non-inflammatory interpretations of TSPO are necessary in certain contexts.