A hormone most commonly known for its role in aiding digestion may also help protect the developing brain from the negative effects of alcohol.
This is the finding of a study by investigators in the Center for Molecular and Human Genetics at The Research Institute and the Department of Psychology at The Ohio State University. The group’s work may help pinpoint developmental stages at which developing babies are at the most risk for fetal alcohol syndrome.
“Clinical studies have suggested that there are critical periods during fetal development when alcohol differentially affects brain and body development,” said Ichiko Nishijima, PhD, investigator in the Center for Molecular and Human Genetics and lead study author. “It is thought that the brain is particularly sensitive to the neurotoxic effects of ethanol during the third trimester of gestation in humans and the first two postnatal weeks in rodents.”
The hormone, secretin, is present within the pancreas, stomach, kidney and several parts of the brain during these developmental times. Although secretin is classified among hormones within the gastrointestinal tract and the brain, the effects of secretin on the developing brain are poorly understood.
To examine the interplay between secretin and the effects alcohol has on the developing brain, investigators studied an animal model of alcohol exposure. Normal mice and mice born without secretin receptors were treated either with a saline solution (as a control) or with saline combined with 20 percent alcohol during a timeframe paralleling the third trimester of human gestation. Investigators then evaluated the resulting brain effects.
Results showed that alcohol exposure negatively affected the brain of all subjects. However, those born without secretin receptors were impacted two-fold. “Our results indicate that secretin plays a neuroprotective role against the neurotoxicity of ethanol,” said Dr. Nishijima. “This hormone is especially important in supporting the survival of neural progenitors of granule cells, cells that give rise to the innermost layers of the cerebellum.”
Although it is not clear exactly how secretin protects against the effects of alcohol in this model, the findings might help develop a preliminary framework of brain development and a timeframe of high-risk toxicity.
Hwang DW, Givens B, Nishijima I. Ethanol-induced developmental neurodegeneration in secretin receptor-deficient mice. Neuroreport. 2009 May 6;20(7):698-701.