Neural cells derived from patients with bipolar disorder (BD) show a difference in the way they migrate as compared to controls, finds a study.
This difference may contribute in a fundamental way to brain tissue repair and assembly.
The neural tube
Brain development starts early during pregnancy. This starts with a single layer of cells that roll up to form a tube called the neural tube. The brain develops at one end of this neural tube.
It is a process that takes up many cell divisions as well as cells migrating through large distances.
“The trajectories of migrating neural precursors lay the foundation for the developing brain. The speed and direction of migrating cells can alter the regional cellular make-up, and, therefore, the wiring of cortical areas,” says Reeteka Sud from Accelerator Programme for Discovery in Brain Disorders using Stem Cells lab (ADBS lab) in NIMHANS and a corresponding author of the paper published in the journal, Disease Models and Mechanisms.
The key result of the work is that the neural precursor cells derived from stem cells from people with bipolar disorder showed a difference in the way they migrated as compared to neural precursors derived from stem cells of people without bipolar disorder (Controls).
BD and brain structure
Bipolar disorder is a severe disabling illness where a person’s mood, energy, activity levels and ability to carry out day-to-day acivities undergo unusual shifts over a period. The illness has a genetic basis and neurodevelopmental origin.
Many studies have documented abnormalities in the brain structure of patients with BD. Some abnormalities include smaller brain size, reduced cortical grey and white matter and decreased number of interneurons in the cerebral cortex and hippocampus regions.
Increased risk
The researchers write in the paper, “Systemic dysregulation may produce the aberrant cellular phenotype, which could contribute to the functional and structural changes in the brain reported for bipolar disorder.” Roughly, this implies that if the irregularities in migration exist in the formative stage, these could form a mature brain that has the sort of abnormalities seen in people with BD.
“These differences perhaps exist, but need not always convert into disease as the changes are too subtle... However, they do increase the risk in general… and that is what we observe,” says Sanjeev Jain, (Retired) Senior Professor of psychiatry, Molecular Genetics Lab, NIMHANS and an author of the paper.
