Fiber photometry reveals spatially stratified and temporally distinct thalamic calcium dynamics under nociceptive stimulation, highlighting a hierarchical hub for pain processing.
Key Points
To investigate the dynamic, nucleus-specific calcium signaling patterns across the thalamus during different intensities of nociceptive somatic stimulation.
Recorded in vivo calcium (Ca2+) signals across multiple thalamic nuclei using fiber photometry under two intensities of nociceptive stimulation.
Performed cluster analysis on evoked signal dynamics and conducted morphological tracing of downstream cortical projections for specific dorsal thalamic nuclei.
All evaluated nuclei displayed rapid Ca2+ increases following nociceptive input, with cluster analysis revealing a medial-to-lateral spatial gradient where medial nuclei exhibited significantly stronger responses.
Thalamic nuclei varied in intensity sensitivity, with the parafascicular nucleus (PF) reaching peak Ca2+ signals fastest and the posterior nucleus (PO) taking the longest.
Morphological analyses revealed divergent downstream projection targets and distinct cortical axonal distribution profiles between the PF and PO nuclei.