You may have heard the idea that the gut is the second brain, but what does that really mean? Maybe it has to do with the fact that there are something like 100 to 600 million neurons in your gut. That's a lot of neurons. That's about as many as you'd find in the brain of say, a fruit bat, or an ostrich, or a Yorkshire Terrier.  And it turns out, this network of intestinal neurons, termed by scientists the "enteric nervous system," can actually have a lot of impact on our daily lives – not just in controlling things like our appetite, but may contribute to our mental well-being — and potentially event to disorders ranging from anxiety to Parkinson's disease.To learn more about this fascinating "second brain", we spoke with Julia Kaltschmidt, a Wu Tsai Neurosciences Institute faculty scholar and an associate professor in the Department of Neurosurgery at Stanford Medicine.LinksKaltschmidt Lab websiteRecent publicationsEpisode CreditsThis episode was produced by Michael Osborne, with production assistance by Morgan Honaker and Christian Haigis, and hosted by Nicholas Weiler. Cover art by Aimee Garza.Thanks for listening! Learn more about the Wu Tsai Neurosciences Institute at Stanford and follow us on Twitter, Facebook, and LinkedIn.