Lithium. A tiny soft silver-white metal that is the lightest of the alkali metals. For years this small metal has been used to treat bipolar disorder as well as manic depressive episodes. During our neurochemistry class this week we discussed an article called “Molecular actions and therapeutic potential of lithium in preclinical and clinical studies of CNS disorders”. We essentially looked at all of the disorders and diseases within the brain that could potentially be treated with the use of lithium. These disorders include: bipolar disorder, autism, stroke, Huntington’s disease, Alzheimer’s disease, Parkinson’s disease, retinal degeneration, Fragile X syndrome, multiple sclerosis, prion disease, HIV, as well as many others. While discussing these, lithium was always used as something that was administered to a specific target in order to stop the dysfunction of certain pathways. By doing this it would usually (at least in rat models) cause either the disease to diminish or at least aid in treating the symptoms. To help explain better how lithium effects different pathways look at the figure below. All of the lines with a flat end on them are where something has been inhibited and all of the arrows show where things have been facilitated. This diagram shows essentially how lithium can inhibit apoptosis using the RTK, Wnt, and NMDA pathways within the brain (inhibition of apoptosis is a good thing!).
While lithium can help treat many disorders in the brain, it is not something we would want to be taking daily to make ourselves healthier. The way lithium works is that it helps regulate the mechanisms in the brain that are already “out of wack” because of a brain disease, which is why it is so helpful in many cases. If a healthy person were to take lithium doses however, it could cause massive and unnecessary pathway malfunctions within the CNS. This metal has recently been used in rat models and not as much in humans yet. Scientists are trying to see what is safe and what will work before trying these treatments in humans. Targeting places in the brain is probably one of the biggest setbacks for using lithium as a treatment for human diseases. Once these targets have been located and tested then hopefully lithium will be used as a treatment for many of these disorders in the future.