View the Show Notes Page for This Episode Become a Member to Receive Exclusive Content Episode Description: Karl Deisseroth is a world-renowned clinical psychiatrist, neuroscientist, and author of Projections: A Story of Human Emotions. In the episode, Karl explains his unique career path that led to the development of optogenetics—a revolutionary technique that uses specialized light-sensitive ion channels to precisely control the activity of select populations of neurons. Karl provides a concise overview of how optogenetics works and how it can be used to better understand mental illness, to identify the neurons responsible for specific behaviors, and to guide development of new treatments. Karl uses his experience as a practicing psychiatrist to provide deep insights into depression, anxiety, autism, and personality disorders and explains the role of optogenetics in mapping out brain regions responsible for common mental health afflictions. We discuss: Karl’s journey through medical school and interest in the brain [5:00]; A profound medical school experience that changed Karl’s career path to psychiatry [17:30]; Karl’s commitment to research and challenges overcome early in his career [27:00]; The state of psychiatry and mental health therapies when Karl started his lab in 2004 [33:15]; Neuroscience 101: fundamentals of neuroanatomy and neurophysiology [38:15]; Traditional techniques for identifying the brain regions involved in specific behaviors [47:15];   Intro to optogenetics and how to get a gene into a neuron [51:15]; How viruses helped make optogenetics possible [1:01:45];   How optogenetics was used to investigate the effects of dopamine neurons [1:15:45]; Appreciating the power of optogenetics [1:22:00]; Investigating and treating anxiety with optogenetics [1:26:45]; Autism and autism-related anxiety, and the potential of optogenetics in treating autism [1:38:00]; Optogenetics as a powerful tool for the discovery and creation of medical treatments [1:45:00]; Karl’s inspiration to write his book, Projections [1:48:00]; Mania and bipolar disorder: evolutionary basis, symptoms, and the high prevalence in North America [1:52:45]; Depression: evolutionary basis and insights from optogenetics [2:03:15]; The effects of trauma early in life [2:18:45]; and More. Sign Up to Receive Peter’s Weekly Newsletter Connect With Peter on Twitter, Instagram, Facebook & YouTube