WHOLE-BRAIN C-FOS IMAGING TO ACCELERATE PRECLINICAL CNS DRUG DISCOVERY

Whole brain c-Fos imaging uses the immediate early gene c-Fos as a proxy for recent neuronal activation. After a stimulus, a drug dose, a behavior or a disease state, c-Fos protein accumulates in activated neuronal nuclei and peaks roughly 1 to 2 hours later. Combined with iDISCO+ tissue clearing and light sheet fluorescence microscopy, every c-Fos-positive cell across the entire mouse brain can be detected, counted and mapped in 3D, providing a brain-wide snapshot of which circuits were recruited.

c-Fos mapping counts the neurons that express c-Fos protein after a treatment and assigns each one to an anatomical brain region. Comparing drug-treated and vehicle-treated animals shows which regions a compound activates, how strongly and at which dose. Because LS-Journey™ maps all 800+ regions of the mouse brain, one experiment reveals the primary target circuits, downstream network effects and potential side-effect signatures of a CNS drug.

The pipeline begins with validated c-Fos immunolabeling of fixed mouse brain tissue. The tissue is cleared using iDISCO+, scanned by light sheet fluorescence microscopy and analyzed at 5 µm isotropic resolution, and all c-Fos-positive nuclei are counted by AI-powered cell segmentation. Each brain is registered to the Perens Common Coordinate Framework (CCF), placing every detected cell into a shared anatomical space. Results are delivered on CNS-Voyager™ with per-region cell density statistics ready for statistical analysis.

c-Fos mRNA rises within 30 to 60 minutes of neuronal activation, and c-Fos protein peaks roughly 1 to 2 hours after the stimulus before returning toward baseline over the following hours. Most whole-brain c-Fos studies therefore collect brains 90 to 120 minutes after dosing or behavior. Our c-Fos study design guide covers timing in detail.

c-Fos is a powerful discovery tool but not a direct recording of neural firing. Key limitations: (1) there is a delay of roughly 1 to 2 hours between activation and peak protein signal; (2) not all neurons express c-Fos, so absence of signal does not mean absence of activity; (3) c-Fos reports correlation, not causation. Follow-up experiments using optogenetics, chemogenetics or electrophysiology are needed to establish causal roles. Used correctly, whole-brain c-Fos mapping is a highly efficient discovery and hypothesis-generation tool.

Yes. Because whole-brain maps capture all activated regions simultaneously, they reveal not only the intended target circuits but also downstream network effects that may correspond to side effects. GLP-1 receptor agonists like semaglutide, for example, activate appetite circuits but also engage nausea circuits in the brainstem. Both pathways are visible in a single whole-brain c-Fos map from a single experiment.

The full LS-Journey™ pipeline, from sample receipt to data live on CNS-Voyager™, takes 2 to 2.5 months. This covers tissue preparation and clearing, light sheet microscopy, AI-assisted image analysis, and atlas registration to the Perens CCF. Contact Vibraint to discuss timelines for your specific project.

A c-Fos study moves through four stages: whole-brain immunolabeling and tissue clearing (iDISCO+), about 4 weeks; light sheet microscopy, 1 to 2 weeks depending on study size; AI-assisted image analysis and atlas registration, 2 to 3 weeks; and an optional formal study or regulatory report, about 2 weeks.

Yes. Labs that already have externally generated light sheet data can submit it for analysis and CNS-Voyager™ upload only, skipping tissue preparation and imaging. This shortens the process to just the analysis stage, about 2 to 3 weeks.

Yes. Some timelines can be adjusted for time-sensitive programs; contact us directly to discuss scheduling for your study.

LS-Journey™ routinely runs studies of up to 48 brains across 6 experimental groups in a single run. Larger or smaller designs can be discussed depending on the study's goals.

The LS-Journey™ c-Fos imaging service currently covers the whole mouse brain, including all major regions such as cortex, hippocampus, hypothalamus, amygdala, basal ganglia, brainstem, and cerebellum. Over 800 annotated structures are resolved through registration to the Perens Common Coordinate Framework. Contact Vibraint to discuss custom workflows or additional species.

CNS-Voyager™ is both a data delivery system and a multimodal analysis environment. In addition to your c-Fos maps, it allows overlay with connectivity atlases, neuronal activity reference datasets, and spatial transcriptomics, enabling you to move from "where does my drug act?" to "what cell types respond?" and "which circuits are downstream?" all within a single interactive browser session.