UC San Diego

We have developed two new tools for tracing neural connections. The first is a means of identifying cells that project to a region of interest within the brain, illuminating these cells with intense fluorescence and allowing their finest morphological details to be seen. This permits either highly detailed reconstruction of the cells' anatomy or their targeting, in live tissue, on the basis of their morphology for physiological study. The second tool is a means of identifying, on a large scale, neurons which are directly presynaptic to either a targeted cell type or indeed a single neuron. Because this technique also results in intensely fluorescent cellular details, this too could be used either for detailed anatomical studies or for physiological ones. This should allow a significantly more precise understanding of the organization of nervous systems than has previously been possible