Stem Cells Help Unravel the Mystery of Bipolar Disorder

Researchers have developed a model of studying the nature and causes of bipolar disorder through stem cells, revealing differences between the cells of bipolar and non-bipolar patients and raising news questions they hope will help them unravel the mysteries of bipolar disorder.

For as long as professionals have been aware of its existence, scientists have remained unsure about what exactly causes bipolar disorder. The disorder, which is characterized by sudden and alarming shifts in mood, has been associated with many possible causes that experts theorize work together to produce various intensities of the illness.

According to the National Institute of Mental Health, experts can agree that risk of bipolar disorder is caused at least in part by genetics. However, previous studies of identical twins have shown that one twin can demonstrate symptoms of the disorder while the other can go throughout their life never showing signs of the illness. This of course has raised some questions about how and why these mysterious bipolar genes are expressed that a research team from the University of Michigan Medical School hopes can be answered using the first stem cell model for bipolar disorder ever created.

According a study published in Transitional Psychiatry, the Michigan team obtained skin cell samples from people with bipolar disorder as well as from people with standard mental health. Exposing these skin cells to carefully controlled conditions that turned them into induced pluripotent stem cells (iPSCs) -- stem cells that share the characteristic of embryonic stem cells that allows them to become any other type of still while still maintaining the genetic information of the original cell. The researchers were then able to turn these stem cells into neurological cells for study.

Authors of the study write that one of the major challenges that researchers face when studying the causes of a neurological condition like bipolar disorder is limited access to viable nervous system tissue for examination. Using this stem-cell method, the researchers were able to make an abundance of tissue to examine bipolar disorder's progression.

Comparing bipolar neural tissue verses non-bipolar tissue, the researchers found that bipolar neurons expressed more genes that effected the sending and receiving of calcium signals between cells. Because these signals are paramount to the development and function of neurons, the research team suspects that genetic differences in early brain development may contribute to the expression of bipolar disorder.

The researchers are excited about these findings, but still raise many new questions. The importance of the study is the success of the stem cell model to observe any differences between bipolar and normal neurological cells at all, and hope to see it being used in future research.

The study was published in Translational Psychiatry on March 25.