Disclosed herein are compositions and methods for imaging nerve cells. The composition comprises a fluorescent dye； and a viral component selected from a neurotropic, replication-defective virus, a viral protein of a neurotropic virus, and a capsid of a neurotropic virus. Although the fluorescent dye in itself cannot penetrate nerve cells, the fluorescent dye is bound to the viral component to form a dye/viral component complex that is capable of penetrating nerve cells.
