A novel probe for precise and symmetric bilateral in utero electroporation in the mouse

In utero electroporation (IUE) has been an invaluable tool for the efficient expression of genes in the developing brain and widely employed in characterizing the molecular mechanisms of circuit formation. However, its application to other fields of neurobiology, including cognitive development, has been hampered by several limitations, including sparse expression, high hemispheric lateralization, and difficulty in targeting specific cortical or hippocampal regions. To address these issues, here we describe a novel IUE approach, specifically designed for use in the mouse, that combines up to four paddle and needle-type electrodes and permits precise, robust, and symmetrical bilateral transfection in a safe and efficient manner. The ability to achieve reproducible symmetric transfection patterns in brain regions involved in cognition will allow more intricate investigations into the molecular and circuit mechanisms of early cognitive development.