A Surgeon’s Mistake Provides Insight into Memory and Learning

In an attempt to localize the part of the brain responsible for hunger, surgeons in Toronto inadvertently identified and stimulated a portion of the brain involving in memory and learning. This finding may lead researchers to develop new techniques for improving brain function in dementia.

The surgeon was attempting to implant a deep brain stimulator into the hypothalamus of an obese man, in order to curb his appetite by stimulating brain cells that suppress hunger. With the patient conscious, in order to respond to the neurosurgeon’s probing, stimulation instead lead to a vivid recollection from over 30 years prior. The patient described a detailed memory of walking in the park with friends, including facial and clothing characteristics. Later, the patient was found to have significant improvements in learning when the electrodes were turned on.

Deep brain stimulation (DBS) is most commonly used to treat Parkinson’s disease, with over 40,000 patients in the US currently receiving this therapy. DBS involving the implantation of tiny electrodes into specific points in the brain that are attached to an external “battery pack.” Stimulation of the subthalamic nuclei in patients with Parkinson’s causes immediate and significant improvements in tremor. Theoretically, DBS could be used for a variety of medical conditions that can be linked to over- or under-activity at a specific location within the brain.

This unintentionally discovery is already being explored. Six Alzheimer’s patients have been implanted with DBS in order to see if they can recreate the findings.

By locating a specific area that responds to stimulation by increasing memory recollection and learning ability, it may be possible to treat dementia and other memory disorders with DBS. Perhaps by stimulating a specific location within the brain substance, patients will be able to recall memories that were previously lost, or will be able to learn tasks that they had forgotten.

Localization of a memory center within the brain will also allow researchers to study this region more closely and potentially develop molecular therapies that stimulate these cells chemically.

Reference

Jeremy Laurance. Scientists discover way to reverse loss of memory. The Independent. 2008.