This thesis is about the essential role that hyaluronan plays in the extracellular matrix of the central nervous system. In our study we used plasmids encoding hyaluronidase enzyme to disrupt the extracellular matrix. We injected the plasmid solution into the ventricles of the mice embryos and applied the method of electroporation to induce the uptake of the plasmid into the cells in contact with the solution. We noticed that the expression of the plasmid disrupted the development of the hippocampus in the mouse.