The puzzle of why people with cochlear implants are more susceptible to meningitis has been discovered by a Victorian researcher. The brain is an incredibly fragile organ. Evolution certainly thinks so -- it has surrounded this mass of nerves and cells with a solid case of bone to guard against physical trauma, and lined its blood vessels with an almost impermeable membrane to guard against chemical and biological threats. As long as these defences remain unbreached, the brain is relatively safe. But sometimes they have to be breached. Cochlear implants bypass damaged hearing systems to directly stimulate the auditory nerves, but to enable this, surgeons must drill through the bone and implant electrodes deep within the inner ear, where they come into direct contact with the nerves.   Full Story