Biology

Dr. Narendrakumar Ramanan 
Centre for Neuroscience, Indian Institute of Science, Bangalore

Astrocytes are the most abundant cell type in the mammalian brain and play critical roles in nearly every facet of brain activity and function. In response to CNS injury and pathologies, astrocytes undergo complex morphological, physiological and functional changes through a process termed ‘reactive astrogliosis’.  Emerging studies show that these changes are dictated by the type and severity of insult to the CNS tissue, and that astrogliosis can be both beneficial and detrimental.  Although it is widely believed that astrogliosis is a fine-tuned process involving many extracellular and intracellular signaling cascades, the molecular mechanisms regulating astrogliosis remain poorly understood.  In this talk, I will explain how astrocytes are generated in the brain during development and describe the experiments that uncovered a genetic mechanism that regulates the generation of neuroprotective reactive astrocytes.  I will present evidence that these reactive astrocytes provide neuroprotection in the mouse brain following ischemic stroke, traumatic brain injury and kainic acid-induced neurotoxicity.