On this week’s Tech Nation, University of Wisconsin math professor JORDAN ELLENBERG, whom you might know from his earlier book, “How Not To Be Wrong”. He talks about “Shape … The Hidden Geometry of Information, Biology, Strategy, Democracy, and Everything Else.” Then MARCIO SOUZA, the President and CEO of Praxis Precision Medicines, describes their research drug modulating GABA, a key neurotransmitter in the brain, and its potential to treat depression, essential tremor, and other conditions.