The Contribution of Thalamocortical Core and Matrix Pathways to Sleep Spindles

Figure 1

Schematic representation of the core and matrix pathways. Spindles are generated in the reciprocal connections between TRN (thalamic reticular nucleus, in gray) and the thalamocortical neurons, belonging to either the core (in blue, labeled with “C”) or the matrix (in red, labeled with “M”) pathway. Neurons belonging to the core and matrix pathways are mostly intermixed inside the thalamus, but individual nuclei might have prevalence of either type. The projections from the TRN are inhibitory, indicated by the square terminals. The core pathways are independent of each other, project to a single brain area, and reach the middle, granular layers of the cortical column. The matrix pathways have a broader and more diffuse fan-out and target more superficial, supragranular layers.