WIM no. 17 Spring 2020

מכון ויצמן למדע The Development of Neural Networks T he adult brain is a complex network of roughly 100 trillion connections among billions of neurons. Proper functioning of this network demands an efficient wiring of circuits, optimized yet flexible enough to handle the uncertainties of daily living. Q How does the brain, with all of its complex neural networks, develop? What happens when the process goes awry? A Scientists will aim to reveal how the diversity of specific types of neurons emerge during development, how neurons migrate to their correct locations, and how neurons’ extensions are guided over long distances to find their targets. Topics will include understanding the formation of neural connections (synapses), remodeling of synapses and circuits, development of sex differences in neural networks, the role of neural support cells, as well as neuronal metabolism. This research will lead to a better understanding of the pathology underlying a variety of diseases and disorders from epilepsy and fragile X syndrome, to a range of mental illnesses. Perception and Action Humans have an insatiable appetite for sensory input—whether conscious or unconscious. Sensory perception provides the immediate ingestion of information, driving our behaviors as we seek out the new. Q How do we sense, and how does the brain combine input from different sensory modalities to form a coherent picture? A Weizmann scientists are exploring a variety of forms of sensory processing to clarify how sensory input translates into action. They are also working to unveil the process of motor action—from the decision to take an action in higher brain areas, to the execution of a movement via commands transmitted to the spinal cord, followed by muscle activation. This research will improve our understanding of sensory disorders and motor diseases, and contribute to efforts to develop sensory substitution techniques, alleviate chronic pain, and develop artificial sensing technologies, such as robotic arms and brain-machine interfaces. Mental and Emotional Health More than 7 percent of global life expectancy years lost to illness, disability, or premature death are caused by mental illnesses, including depression, anxiety, schizophrenia, and bipolar disorder, among other debilitating conditions. Q What prompts mental illness, what promotes resilience, and how can we manipulate these processes? A Scientists in this center will employ integrated molecular, biochemical, genetic, and behavioral methods in state-of-the-art preclinical models to investigate neural pathways. Others will use Centers of Investigation 24–25 S P R I N G 2 0 2 0 Weizmann MAGAZINE