Children with the neurogenetic disorder Christianson Syndrome experience delays in language and learning; they may also have seizures, and display symptoms of autism. Scientists say these disorders are a result of stunted brain cell growth, which occurs because of a mutation in the gene that produces the protein NHE6—a protein also mutant in several forms of autism.
Neurons in human brains with the mutant gene don’t branch as robustly or form connections as well as neurons in normal brains. But researchers at Brown University may have found a way to restore the ability of these cells to grow properly.
In their study, published in the journal Neuron, senior author Dr. Eric Morrow and his team describe a signaling pathway for neuronal growth involving NHE6. Using a mouse model with an NHE6 gene mutation, they found that reduced levels of NHE6 combined with increased acidity in a cell’s endosome, results in a depletion of the receptor protein TrkB, a key player in the growth and branching of axons and dendrites.