A very different type of neuroprostheses is under development at the laboratory of Theodore Berger at the University of Southern California in Los Angeles. The aim: To replace the hippocampus, a tiny but important structure of the brain which is located in the lower regions of both hemispheres. The hippocampus seems to play an important role in memory formation. It is thought to be some kind of intermediate station before the memories enter long-term storage.
To create an artificial hippocampus was a major task and took the scientists about ten years (more). The chip, which is about to be tested in rats, will sit outside the skull rather than inside. It would communicate with the brain via two arrays of electrodes that are placed on the both regions where the hippocampus originates, respectively. The big question is: Will the behaviour of the rats change with the chip or won't it? If it works, the chip might help to restore memory in patients with Alzheimer's, or stroke - one day in the far future...