The parasympathetic nervous system appears to be formed in a way that is different from what researchers previously believed, according to new research from the Karolinska Institute.
The new study, published in the journal Science, alter a fundamental principal of our understanding of how the peripheral nervous system develops in the body. Researchers at Karolinska Institutet have made three-dimensional reconstructions of mouse embryos. These show that the parasympathetic neurons are formed from immature glial cells known as Schwann cell precursors that travel along the peripheral nerves out to the body’s tissues and organs. The immature cells have the properties of stem cells and may be the origin of several different types of cells. For example, the researchers behind this new study have previously demonstrated that the majority of our melanocytes (pigment cells) are born from these cells.
“Our study focuses on a new principal of developmental biology, a targeted recruitment of cells that are probably also used in the reconstruction of tissue. Despite the elegance, simplicity and beauty of this principal, it is still unclear how the number of parasympathetic neurons is controlled and why only some of the cells transported by nerves are transformed into that which becomes an important part of the nervous system”, says Igor Adameyko at the Department of Physiology and Pharmacology who, together with Patrik Ernfors at the Department of Medical Biochemistry and Biophysics, is responsible for the study.
The researchers found that the entire parasympathetic nervous system arises from these progenitor cells that travel along the peripheral nerves. The hope is that this discovery will open up the possibility of new ways to treat congenital disorders of the autonomous nervous system using regenerative medicine.
Photo: Dr. Igor Adameyko. Credit: Gustav Mårtensson