Some brain cells are naturally protected against a stroke – and now we know why. Jack Mellor at the University of Bristol, UK, exposed slices of rats’ hippocampi to the low-oxygen conditions typical of a stroke. Neurons in the hippocampi known to resist stroke damage acted differently from a population of vulnerable cells: they removed receptors for the neurotransmitter glutamate from their cell surface, reducing their sensitivity to the chemical. Glutamate floods the brain during a stroke.
