vGLUT2 -immunoreactive terminals in the macaque thalamus. A, High-power light microscopic image of a vGLUT2-immunostained section using DAB-Ni as a chromogen from the VPL. vGLUT2 labels large irregularly shaped terminals (arrows). B, High-power electron micrograph of a vGLUT2-positive terminal (b) labeled by silver intensified gold particles (small black dots). The terminal displays the ultrastructural features of RL-type terminals, including large size, multiple mitochondria, puncta adherentia (arrowheads), synapses (arrows). C, Regional distribution of large vGLUT2-positive terminals at four coronal levels of the macaque thalamus arranged from rostral to caudal levels. Note the absence of subcortical driver inputs from large thalamic territories. Scale bars: A, 20 μm; B, 0.5 μm. APul, Anterior pulvinar; AV, anteroventral; bsc, brachium of superior colliculus; CM–Pf, centromedian–parafascicular; fr, fasciculus retroflexus; Ipul, inferior pulvinar; LD, laterodorsal; LGN, lateral geniculate nucleus; LPul, lateral pulvinar; MD, mediodorsal; MGN, medial geniculate nucleus; MPul, medial pulvinar; VA, ventral anterior; VL, ventrolateral; VPL, ventral posterolateral; VPM, ventral posteromedial; Rt, reticular thalamus.