Neuroregeneration, neurodegeneration and brain recovery following ischaemic stroke: a comparative review of animal models and humans

Stroke is a leading cause of healthcare burden in the aging population with a rapidly rising prevalence worldwide. Ischaemic strokes account for 85% of the strokes. The key to recovery of brain functions following an ischaemic stroke depends on two arms: 1) restoration of lost or damaged neurones and, 2) survival of neurones that were not killed by the injury. Hence, the recovery could be hastened by promoting neuroregeneration and preventing neurodegeneration. During the last five decades, animal models showed promising results in the field of neuroregeneration, which was long believed to be impossible. Furthermore, animal studies with stroke lead to the discovery of the novel concepts of epigenetic inhibition in nerve growth, upregulation of apoptotic genes, neuroinflammation and metabolic dysregulation which contributed to neurodegeneration. However, it is debatable if these findings can be replicated in human brains, in order to develop potential therapeutic strategies.