Benchmarking of tools for axon length measurement in individually-labeled projection neurons
Fig 3
Reconstruction of the complete axonal (blue) and dendritic (red) trees of 3 individually-labelled thalamocortical neurons used for the practical implementation of the length estimation methods in the laboratory. A. Class 1 neuron from the lateral geniculate nucleus (LGN) arborizing focally in primary visual cortex (V1). B. Class 2 neuron from the posterior nucleus (Po) arborizing focally in 3 separate cortical areas: primary motor cortex (M1), primary somatosensory cortex (S1) and secondary somatosensory cortex (S2). C. Class 3 neuron from the lateral posterior nucleus (LP) arborizing over a large extension of the temporal association cortex (TeA). D-I. Brightfield microscope images of 50 mm thick coronal sections showing different parts of the labeled neurons after immunostaining for GFP and ABC-DAB-Nickel intensification. D. Cell body and dendrites of a Class 1 neuron. E. Axonal arborization in the cortex of a Class 1 neuron. F. High—magnification details of the axonal branches shown in E. G-H. Axonal arborizations of the Class 2 neuron in the motor cortex (G) and the primary somatosensory cortex (H). I. Axonal arborization in the temporal cortex of the Class 3 neuron. Note the sparse distribution of the axonal fragments (Arrowheads). Scale bars: A-C, 500 μm; D, E, G, H, I, 100 μm; F, 10 μm.