Colds More Dangerous Than Previously Thought - They May Trigger Memory Loss

A recent study conducted by researchers at the Mayo Clinic found that there is a family of viruses met in illnesses from common cold to polio which can also infect the brain and cause neurological damage and - consequently - memory loss. Writing in the Neurobiology of Disease Journal, researchers involved in the study pointed out the fact that these particular family of viruses can infect individuals all throughout their lives and eventually lead to a steady decline of the cognitive function.

"Our study suggests that virus-induced memory loss could accumulate over the lifetime of an individual and eventually lead to clinical cognitive memory deficits. We hypothesize that mild memory and cognitive impairments of unknown etiology may, in fact, be due to accumulative loss of hippocampus function caused by repeated infection with common and widespread neurovirulent picornaviruses," wrote Charles Howe who reported the findings of the current study in the medical journal.

Picornaviruses form the family of the viruses which Mayo Clinic researchers suspect to affect one's brain in the course of his lifetime and trigger memory loss and cognitive decline in old age. The study was conducted on mice that have been previously infected with the Theiler's murine encephalomyelitis virus, which is very similar to the human picornaviruses. After that, trial animals had to walk through a maze and almost none of the mice succeeded in fulfilling the task.

When the task was finished and researchers noted that the animals were unable to manage to navigate through the maze, the team killed the mice and closely analyzed their bodies and brains. Results brought to light the fact that the virus affected the hippocampus area of the mice, an area which is responsible for learning and memory abilities.

Mayo Clinic researchers concluded: "Our findings suggest that picornavirus infections throughout the lifetime of an individual may chip away at the cognitive reserve, increasing the likelihood of detectable cognitive impairment as the individual ages. We think picornavirus family members cross into the brain and cause a variety of brain injuries. For example, the polio virus can cause paralysis. It can injure the spinal cord and different parts of the brain responsible for motor function. In the murine (mouse) virus we studied, it did the same thing and also injured parts of the brain responsible for memory."