Current Stimulation May Keep Visual Neurons Alive After Injury – But at a Cost
Optic nerve neurons may be saved from death after a lesion – but for that they need to disconnect
Electrical stimulation of the brain by applying current to the eye may help retinal nerve cells to survive injury. While these neurons may not be restored to full function, they are prevented from dying. But to achieve survival, their interconnections, the dendritic tree, needs to disconnect rapidly for the protective action to unfold. In a study, researchers from Magdeburg University (Germany) and The Chinese University of Hong Kong report that for rats and mice, repetitive transorbital alternating current stimulation (rtACS) may help preserve visual neurons from cell death after injury. Because the tissue at the back of the eye, the retina, is part of the brain, researchers can directly observe how brain cells react in the living animal. The researchers repeatedly monitored neurons in both rat and mouse retinas after an optic nerve injury and measured neuronal death after this lesion. Surprisingly, a neuroprotective treatment with electrical alternating current stimulation increased cellular survival in the eye´s retina, but it also induced a fast and complete stripping-off of the neuron’s dendritic tree. The dendrites are like a tree receiving many thousands of signals from other neurons. This enables them to process visual information and then transmit the signals along the optic nerve towards the brain.
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