...(AAV), have been used for tracing and visualizing motor, visual, and auditory neuronal circuitry in vivo...away from the site of application and aid in visualization of the morphology of individual neurons, including...colorimetric product or are fluorescent. While dyes usually spread unidirectionally, there are some reports...that their diffusion across the synaptic cleft is usually severely impaired, and only few reports exist about...number of connections, or the “connectome”, to be visualized in a uniform and standardized way (Oh et al.,...An additional desirable property for network visualization would be the ability to spread trans-synaptically...attributes and their use has allowed for the visualization of single connection networks within the rodent...