Media 4 - Visualization of the preganglionic neuron dendritic field in the lumbosacral intermediotal lateral column

Visualization of the dendritic field via retrograde filling of lumbosacral (L6-S1) preganglionic neurons in rat spinal cord. Microinjection of the retrograde tracer cholera toxin subunit B (CTB) into the major pelvic ganglion (MPG) of a female rat was taken up by sacral preganglionic neurons in the intermediolateral column (IML).

Whole tissue immunolabelling and clearing using a modified form of iDISCO for spinal cord enabled the imaging of retrogradely-filled neurons. Large volume imaging was performed on the light sheet microscope with a 12x lens (Ultramicroscope II, Miltenyi Biotec). Punctate appearance of CTB granules along dendrites was segmented using the Spots function in Imaris (Bitplane), while the Surfaces function was used to segment the preganglionic neuron somata.