Researchers have claimed that the human nose acts as a gateway to several types of viruses linked to brain disorders. According to the researchers, the nose can be a portal to herpes virus-6(HHV-6), which is a member of herpes viruses family. The virus is responsible for brain disorders, such as sclerosis, encephalitis and epilepsy. According to Steven Jacobson who conducted the research, the virus also causes roseola, a disease common among infants, which leads to high fever and skin rashes. The researchers analysed tissue samples from autopsies, including a patient who had multiple sclerosis, to find out how HHV-6 enters the brain. Although viral DNA was seen throughout the brain, it was found largely in the olfactory bulb, a region of the brain detecting odours. Until now, it has been a mystery as to how the virus enters the brain given our intelligence which is largely protected by the so-called blood-brain barrier that filters out many germs and drugs. The researchers also found that nasal cavity might harbour the virus even in healthy people.