A developmentally transient, functional thalamo-cortico-reticular loop generates spindle-bursts to refine visual circuits
Matthew Colonnese
Laboratory of Systems Neural Development
George Washington University Medical School, US

Résumé
Different epochs during development require unique patterns of activity to effectuate proper synaptic plasticity and circuit formation. During the initial formation and refinement of thalamocortical circuits, spindle-bursts synchronize firing throughout the depth of cortex and between the associated relay thalamic nucleus and its cortex. In the visual system, these oscillations arise in the relay thalamus in response to spontaneous retinal waves, suggesting they are necessary for the refinement of visual topography. Here, we identify the circuit basis for spindle-burst generation in visual thalamocortex as the unique connectivity of relay thalamus, cortex, and the inhibitory thalamic reticular nucleus (TRN) present during the period of retinal waves. Blocking spindle-bursts during development through inhibition of the TRN causes a reduction of visual topography in the thalamocortical projections. Development of direct relay thalamus excitation to TRN ends spindle-burst generation by decreasing inhibitory delay. Our results show the critical role of thalamic circuit maturation in the developmental matching of activity to circuit plasticity.

Invité par Rosa Cossart

Vendredi 3 octobre 2025 à 11h – salle de conférence de l’Inmed