Zhengqing Hu, MD, PhD, Dr.Zhengqing Hu is an Assistant Professor in the Department of Otolaryngology–Head and Neck Surgery at Wayne State University School of Medicine, has been able to culture the neural stem cells that give rise to spiral ganglion neuron (SGN) -like cells, auditory cells critical for sound perception. He hopes that his work will lead to replacement cells for damaged auditory neurons in the inner ear that can help restore hearing in people with hearing loss.
Dr. Hu collected cells from the inner ear of mouse embryos, and using novel techniques, was able to separate out the neural stem cells that would ultimately give rise to the SGNs during normal embryonic development. He was then able to multiply these neural stem cells to form a large batch of them for further experimental procedures – in effect, cloning the neural stem cells.
Next, Dr. Hu wanted to investigate how to ensure that these cloned neural stem cells will be able to carry auditory signals, as they would need to if implanted into the inner ear. He treated the cells with several neurotrophic factors- substances produced by the body that stimulate nerve growth. He found that one such factor, neurotrophic growth factor (NGF) was most effective in causing the cells to grow and also helped encourage them to become SGN-like glutamatergic neurons. This means that the cells were able to use glutamate, another substance important in proper nerve function, to carry electrical impulses. Auditory neurons use glutamate to help carry auditory impulses.
Next, Dr. Hu transplanted these neurons into the brain slices of mice to see if they would make the proper connections with central hearing neurons. His next step is to dissect the brains and see how the implanted neurons fared.
So far, his results suggest that embryonic nerve cell implants may provide a possibility for treatment of profoundly deaf patients.