[Fast and aimed delivery of voltage-sensitive dyes to mammalian brain slices by biolistic techniques]

Fast voltage-sensitive dyes (VSD) are widely used in modern neuroscience for optical recording of electrical potentials at many levels, from single cell compartment to brain areas, containing populations of many neural cells. The more lipophilic a VSD, the better signal-to-noise ratio of the optical signal, but there are no effective ways to deliver a water-insoluble dye into the membrane of live cell. Here we report a new protocol based on rapid biolistic delivery of VSDs, which is optimal for further recordings of optical signals from live neurons of rat brain slices. This protocol allows us to stain locally (150 mkm) neural somata of brain structures with a Golgi-like pattern, and a VSD propagates even to distant neurites of stained cells very quickly. This technique also can be used for rapid local delivery of any lipophilic and water-insoluble substances into live cells, further optical recording of neural activity, and analysis of potential propagation in a nerve cell.