Scientists at Rutgers University have discovered new insights into the basic brain systems of autism spectrum disorder. The study, which occurred over a period of 7 years, discovered that a particular gene mutation recognized to be associated with ASD leads to an overstimulation of brain cells that’s considerably higher than in brain cells without the mutation.
In order to make these discoveries, the scientists used cutting edge methods, such as raising human brain cells from stem cells and transplanting them into mouse brains.
Experts said their work demonstrates the possibility of a new method to learning brain disorders.
The scientists found in Molecular Psychiatry that a mutation in the Neurologin-3 gene was discovered to induce a greater degree of interaction with a system of transplanted human brain cells in mouse brains. This particular overexcitation, quantified in experiments by researchers, shows itself as a surge of electrical activity more than double the level observed in brain cells with no mutation.
“We were shocked to discover an improvement, not a deficit,” said Zhiping Pang, an associate professor in the Department of Neuroscience and Cell Biology in the Child Health Institute of New Jersey at Rutgers Robert Wood Johnson Medical School as well as the principal author on the research. This particular gain-of-function in those specific cells confirmed by our analysis results in an imbalance of all the neuronal network of the human brain, interrupting regular information flow, “he said.
The interconnected mesh of cells that form the human brain has special “excitatory” cells which trigger electrical activity, balanced by “inhibitory” brain cells which curtail electrical pulses, Pang said. Researchers discovered the mutation threw the mouse brains out of kilter, leading to the huge burst of electric activity.
Autism is a developmental condition brought on by differences in the human brain. Based on the Centers for Disease Control and Prevention, more or less one in forty four kids are diagnosed as having this condition.
Research suggests autism may be the result of disruptions in normal brain development quite early on in development, based on the National Institutes of Health’s National Institute of Neurological Disorders as well as Stroke. According to the NIH, interruptions in genes which regulate brain growth and regulate how brain cells communicate with one another might be the result of mutations in genes.
Pang stated: “So much of the root causes of autism are not known, and that hinders the development of effective therapeutics. “Using human neurons produced from stem cells as a model system, we desired to know why and how a particular mutation leads to autism in humans.”
The scientists utilized CRISPR technology to alter the genetic material of human stem cells to produce a series of cells having the mutation they wanted to study, and then produced human neuron cells carrying this particular mutation. CRISPR, an acronym for clustered frequently interspaced short palindromic repeats, is a distinctive gene editing technologies.
The scientists created human neuron cells and inserted them in the brains of rats, one half with the mutation as well as more than half without. From there, researchers evaluated the electrical activity of particular neurons using electrophysiology, a branch of physiology which examines the power properties of biological cells and compared it with other scientists. Based on the dimensions of the subject of study, electrical current or voltage changes could be quantified on a number of scales.
“Our results suggest that the NLGN3 R451C mutation significantly impacts excitatory synaptic transmission in human neurons, thereby triggering changes in general network properties which could be associated with psychological disorders,” stated Pang. “We consider this as really crucial information for the industry.’
He expects a lot of the methods developed to carry out the experiment to be utilized in future research studies to learn the basis of some other brain disorders, including schizophrenia.
“This study highlights the possibility of utilizing human neurons as a model system to study psychological disorders and create new therapeutics.”
The study was endorsed by the National Institute of Mental Health, the Governor’s Council for Medical Research and Treatment of Autism and the Robert Wood Johnson Foundation.
DOI: 10.1038/s41380-022-01834-x
