Is it ethically permissible for a human parent-to-be to consent to genetic modification of their embryo such that it installs halorhodopsin or channelrhodopsin into neural membrane in specific brain regions by adulthood? This would be to allow targeted inactivation or potentiation of said regions for the sake of experimentation. I'm assuming that this could be done without harming the development of the embryo, that there are no side effects, and that the genetically modified person would, of course, be the only one to decide whether or not they participate in experiments that leverage such modifications