re: your comment &#x27;how do you stop anything in the brain - cut the brain out ?&#x27;<p>No, you can still design chemicals and peptides that could cross the blood brain barrier via adsorptive endocytosis, saturable transporters and trans-membrane diffusion.<p>Drug Delivery to the Brain: <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Drug_delivery_to_the_brain" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Drug_delivery_to_the_brain</a><p>Modes of Transport: <a href="http:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pmc&#x2F;articles&#x2F;PMC2697631&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.ncbi.nlm.nih.gov&#x2F;pmc&#x2F;articles&#x2F;PMC2697631&#x2F;</a>