Schizophrenia has been linked to maternal vitamin D levels
Researchers used molecular imaging technology to confirm the role of vitamin D in early brain cell development.Researchers used molecular imaging technology to confirm the crucial role of maternal vitamin D levels in the development of brain cells that produce dopamine, a feel-good chemical. This discovery provides a better understanding of the mechanisms that underlie developmental disorders of the nervous system, such as schizophrenia.
A team of researchers from the University of Queensland's Brain Institute built on past research to further explore the link between vitamin D, dopaminergic neurons and schizophrenia using molecular imaging technology.
Scientists created dopamine-like neurons to replicate the differentiation process that occurs during embryonic development. Neurons were cultured with and without the hormone calcitriol. Vitamin D from food is inactive until it undergoes two enzymatic reactions in the body, the second of which occurs in the kidneys, where it is converted to calcitriol, the active form of vitamin D. Calcitriol binds to the vitamin D receptor and activates it in the cell.
The researchers found that vitamin D affects not only cell differentiation but also neuronal structure.
"We found that the altered differentiation process in the presence of vitamin D not only causes cells to grow differently, but also engages mechanisms to release dopamine differently," said Darryl Ailes, corresponding author of the study.
By mechanisms, he means neurites, the outgrowths that grow out of the body of the neuron cell. They are essential for sending and receiving signals from other parts of the nervous system. The researchers found that the number of neurites increased markedly, and the distribution of the proteins responsible for dopamine release within them changed.
Using a new imaging tool, false fluorescent neurotransmitters (FFNs), the researchers analyzed how dopamine uptake and release changed in the presence or absence of calcitriol. FFNs are low-molecular-weight dyes that accurately mimic the action of a neurotransmitter such as dopamine. They allow visualization of both storage and release of single molecules in nerve endings.
They found that compared to controls, dopamine release was enhanced in neurons grown in the presence of calcitriol. "This is strong evidence that vitamin D affects the structural differentiation of dopaminergic neurons," the scientists wrote.
Using FFN to target and monitor individual dopamine molecules meant that the researchers were able to confirm the hypothesis that vitamin D levels during development affect the formation of dopamine-producing neurons. They believe that early changes in the differentiation and function of dopamine neurons may lead to the dopamine dysfunction seen in adult schizophrenia.
The researchers plan to find out if other schizophrenia risk factors from the environment, such as low oxygen levels or infection during pregnancy, affect the development of dopamine neurons.