# \#274 – Karl Deisseroth — Depression, Schizophrenia, and Psychiatry **Covers**:: **Source**:: [\#274 – Karl Deisseroth — Depression, Schizophrenia, and Psychiatry](https://share.snipd.com/episode/4a043c08-ba7b-42de-a8e8-cf53560b5a45) **Creator**:: [[Lex Fridman Podcast]] # Highlights ##### ^308602497 Goto: https://share.snipd.com/snip/d4f51c54-cd75-436d-8177-6cbe53a8e559 ###### ^308602497q The Lachrymal Glands role in crying Summary: There are long range projections that come so where, where is crying generate? This is a confusing thing about it. So we have a little tear doced the lachrymal gland that leads to the release of fluid. It ejects fluid and it comes out. And those, of course, that whole system was designed to keep the eye ean, to wash out particulare irritants. As long as we've had eyes and have been out of the water in our evolution, we've needed this sort of thing. Transcript: Speaker 1 There are long range projections that come so where, where is crying generate? This is a confusing thing about it. So we have a little tear doced the lachrymal gland that leads to the release of fluid. It ejects fluid and it comes out. And those, of course, that whole system was designed to keep the eye ean, to wash out particulare irritants. So it's long standing. As long as we've had eyes and have been out of the water in our evolution, we've needed this sort of thing. So long standing biological structure, recently coopted, it seems, by our evolution as social or primates. Now, how could that happen? Well, the lachrymal gland is controlled by structures in the ponds, which ist deep in our a just above our neck, between our neck and our head, and reflecting its ancient origin, right as you go farther down toward the spinal cord, these are the more basic, early evolved structures in the ponds. That's where breathing is controlled, ter aducta contraction. And what we've found, and with optogenetics, we to sort this out, there are long range projections from fear and anxiety regions in the forebrain that project all the way to the ponds, in and around those areas. The reason those are there, we think, is to regulate the respiratory rate changes, the breathing changes, of fear and anxiety. So we know when we are in a state of fear and anxiety we need, we cope better if we have elevated heart rate, eleva respiratory rate, more blood pumping around, more oxygenated blood. We're ready to meet the threat if it happens. All those cells are down there in the ponds too, right next to the lachrymal gluck ducked the tear gland nerons. And so almost certainly thi, fear anxiety induced crying, arose from a very slightly misdirected long range projection that was there to regulate breathing. And a little twist, just a little misdirection, a little missing of one sign post to stop here. Going on a little farther getting to the lachrymal gland, nerons gave us crowing. ^308602497