Host: Professor Pierre Magistretti
Adult hippocampal neurogenesis results in the continuous generation of new neurons in the dentate gyrus of the hippocampus throughout the entire lifespan. This process is crucial for brain plasticity and can be affected by multiple factors. In this talk, I will share data on how we are modulating adult hippocampal neurogenesis via different modalities. Primarily, we have shown that an inflammatory insult to the adult rat brain, whether in the cerebrospinal fluid of the lateral ventricles or targeting the substantia nigra, had a negative effect on proliferation of stem/progenitor cells in the hippocampus. Next, we focused on amplification of neurogenesis by means of brain stimulation through electrical or chemical modalities. We first electrically stimulated the anteromedial thalamic nucleus, an important area in the limbic system which possess connections to the hippocampus. We showed a stimulation-induced increase in neurogenesis which is specific to regions connected with the hippocampus, while stimulation of an unconnected thalamic area had no effect. We then used chemical kainic acid stimulation targeting the cell bodies of the same anteromedial thalamic area which also induced an increased level of hippocampal neurogenesis. Finally, we succeeded in inducing hippocampal neurogenesis by a non-invasive chemical using the laughing nitrous oxide gas. Notably, and after establishing a posttraumatic stress disorder (PTSD) model that exhibited reduced neurogenesis, nitrous oxide gas exposure resulted in a significant increase in neurogenesis. All in all, we have succeeded in modulating adult hippocampal neurogenesis using different modalities and we hope to eventually target the functional correlation of hippocampal neurogenesis with the cognitive behavior in rats.
Dr. Chamaa received her Doctoral Degree from the Faculty of Medicine at the American University of Beirut in Lebanon. She is currently working as a research associate in the Department of Anatomy, Cell Biology and Physiological Sciences where she is continuing her work in the comprehensive neuroscience laboratory. Her general research focus is hippocampal neurogenesis and studying multiple factors modulating it for its potential application in neurological and neuropsychiatric disorders. Her scientific interest also lies in experimental research of post-traumatic stress disorder, in the neuroscience of pain and in behavioral neuroscience. She has a unique expertise in brain stimulation across two different modalities (electrical or chemical deep brain stimulation). She has presented her work in multiple regional and international meetings. She has received two awards from the society for neuroscience (SfN) including the Dr. Raniyah Ramadan Young Arab Neuroscientist travel award and Al-Ashwal Award for Outstanding Neuroscientists in MENA region.