a, High magnification views of representative GCs from callosal projection neurons immunolabeled for mTOR, equivalent to Fig 6a mTOR panel, but with a distinct mTOR antibody to independently confirm dense focal mTOR in GCs. Overlay images, top; heat maps of the same GCs below. b, Example of TOR labeling (red in two left panels; heat map in right panel) in 3-day cultured neurons. A GFP-labeled axon from an electroplated trans-hemispheric neuron displays dense focal mTOR in its GC (arrow) compared to adjacent cell bodies (asterisks; DNA in blue indicates nuclei). Two other unlabeled GCs in the field can be recognized by virtue of their dense focal mTOR labeling alone (arrowheads). c, Example of dendritic GCs (arrows) lacking mTOR, juxtaposed to an unlabeled GC (arrowhead) with prominent mTOR focus. Bars in each of a, b, c (lower right of each panel) indicate mTOR intensity heat-map color range, as well as 10 µm scale.