Background
Neuronal activity-dependent gene expression plays a critical role in the development and maintenance of neural circuitry during development and throughout life.
This makes its study essential for understanding how patterns of neuronal activity change or remain unchanged across different regions of the brain in response to specific stimuli, experimental paradigms, or pharmacological treatments.
How We Study Neuronal Activity
Neuronal activity can be studied using various techniques, including the measurement of immediate-early gene (IEG) expression.
At Translucence Biosystems, we study neuronal activity responses to experimental treatments by measuring immediate early gene expression across the entire brain. To do this, we employ our modified iDISCO+ tissue clearing protocol to render intact brain samples optically transparent. This protocol, coupled with a well validated cFos antibody and our proprietary Npas4 antibody, allows us to capture whole-brain snapshots of recent neurological activity.
Utility of Npas4: A Precise Marker of Neuronal Activity
The immediate-early gene (IEG), cFos, is widely used as a go-to marker for detecting neuronal activity. However, cFos expression is also associated with other signaling pathways including cAMP elevations, neurotrophins, and other paracrine factors, limiting its specificity as a marker of pure neuronal activity.
Npas4 is a more precise marker, with expression finely tuned to increases in neuronal activity and the subsequent influx of Ca2+.
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AI-Powered Whole-Brain Cell Segmentation and Quantification
The Translucence Teravoxel ToolKit (3TK), a part of our Voxels software enables whole-brain automated identification of Npas4 and cFos cells in iDISCO+ cleared brains.
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Brain-Wide Quantification of Npas4 and cFos Induction
The Translucence Teravoxel ToolKit (3TK) software uses AI-powered workflows to identify and segment individual Npas4(+) and cFos (+) neurons throughout the cleared and stained intact mouse brain. Then, using our Voxels software, each brain and its segmented cells are computationally warped to the Allen Reference Brain to determine Npas4 and cFos expression metrics across hundreds of brain regions.
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Summary
Translucence Biosystems leverages Npas4, a precise marker of neuronal activity exclusively regulated by calcium-dependent signaling downstream of neuronal activity, and cFos to provide rich whole-brain measurement of recent neuronal activity in response to various behavioral, pharmacological, or genetic manipulations.
