10+ hours of podcasts, in 5 minutes.
12 quotes from 1 episode on Huberman Lab, each with a timestamped link to the source.
Scott Kanoski states that the gut directly controls memory formation through the vagus nerve. Chewing and swallowing food triggers an immediate surge of acetylcholine in the hippocampus, allowing an animal to remember exactly where it found a meal.
Neurobiology researchers still debate whether newer GLP-1 weight loss drugs like Wegovy actually cross the blood-brain barrier.
“Whether these newer generation GLP-1 drugs like Wegovy are getting into the brain is less clear. Really again controversial…”
Cooking food at high temperatures generates chemical byproducts called advanced glycation endproducts that eliminate protective bacteria in the gut.
“And when you heat this food up is there's chemical byproducts of this process. They're called advanced glycation endroducts. The acronym is AGES.”
From Sugar and High Heat Alter Gut Bacteria That Control Memory
Scott Kanoski notes that clear answers on human gut health remain rare because scientists only finished mapping bacterial genetics around 2012.
“I don't think there is a clean answer and and part of the reason for that is in 2012 that's when the approximately when the human microbiome project ended and before that point we didn't really have an idea about the genetic makeup of the bacterial population in the human gut…”
From Sugar and High Heat Alter Gut Bacteria That Control Memory
Sensory vagus fibers transmit data from the stomach to the brainstem. The signal then passes to acetylcholine-producing neurons in the medial septum that wire straight into the hippocampus to control memory.
“If you leion the vagus nerve the as it's coming out of the gut the gastrointestinal intervating components of the nerve animals show hippocample dependent uh memory impairments…”
From How Mealtime Gut Vagus Signaling Drives Hippocampal Memory
“We've identified how this information gets to the hippocampus. So from the brain stem there's an input to the medial septum and then there's a acetylcholine producing neurons in the medial septum are then intervating the hippocampus.”
From How Mealtime Gut Vagus Signaling Drives Hippocampal Memory
Chewing and swallowing cause an immediate surge of acetylcholine in the brain. Scott Kanoski notes this chemical spike allows animals to remember the location of a meal so they can return later.
“And what we found is if you if you track the acetyloline release into the hippocampus when the animals are actively eating so they're holding food, they're chewing it, they're swallowing, the acetyloline levels are ramping up when that's happening.”
From How Mealtime Gut Vagus Signaling Drives Hippocampal Memory
“We think that that elevated postprandial level of acetyloline hippocampus is to allow the animals to remember what what the hell's going on, you know, like just ate this meal. Where am I? Can I get back here and do this again?”
From How Mealtime Gut Vagus Signaling Drives Hippocampal Memory
Transferring gut microbes from sugar-fed subjects into unexposed animals creates immediate cognitive deficits. Timed stimulation of the vagus nerve can reverse these diet-induced memory impairments.
“And then in that state we enriched this population into the gut and the animals showed memory impairments even though they had never consumed sugar.”
From Sugar and High Heat Alter Gut Bacteria That Control Memory
“We have shown that these devices can rescue the memory impairments from an unhealthy diet.”
From How Mealtime Gut Vagus Signaling Drives Hippocampal Memory
The sensory vagus nerve features built-in receptors for GLP-1. Severing this nerve blocks the hormone from reducing food intake, demonstrating that appetite suppression happens locally in the gastrointestinal tract.
“The vagus nerve innervates our GI tract and there's receptors for GLP-1 on the terminal…”
“If you do a selective lesion to the sensory vagus nerve as it comes up from the GI tract to the brain and then inject GLP-1, it's not effective in reducing food intake…”
“…the peripheral GLP-1 and the central GLP-1 have very similar effects. So they're involved in hunger suppression, but they seem to be operating independently.”
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