Introducing the brain: vagus nerve organ signals (Introduction)

by David Turell , Monday, March 21, 2022, 15:43 (766 days ago) @ David Turell

You can't live without them; the automaticity is necessary:

https://medicalxpress.com/news/2022-03-revealing-brain-body.html

"The human brain is a busy organ—detecting signals from all over the body as it undergoes change throughout the day. When the lungs inhale an irritant, the body knows to cough. Or when the stomach ingests toxins, it induces vomiting. The brain plays a role in both.

"Now, in a new study that aims to understand how different signals in the body are coded in the vagus nerve—the cranial nerve that sends information to and from the brain about internal organ function—Yale researchers have found that the signals have three key features that are independently coded by vagal sensory neurons. They are: which organ a signal is coming from, which tissue layer within the organ the signal is coming from, and what the stimulus is. This coding enables the high precision achieved by the brain.

"The body's ability to sense changes within itself is called interoception, a process that is essential to survival. This body-to-brain connection is made through the vagus nerve, and the signals received by that nerve are coded independently by specialized vagal sensory neurons.

"'This is the first time we actually know how different body signals are being represented through the vagal interoception system to the brain in a very precise and accurate manner," says Chang. "We know that the brain can very precisely discriminate signals, but what is the biological reason for that discrimination?"

"'By looking at the genetic signature of the vagus nerve, we were able to know which organ each neuron projected to along the body's rostro-caudal axis," says Chang. "So in summary, our first finding is that there are genetic codes for visceral organ information in the vagus nerve." (my bold)

"Furthermore, each of our organs is made up of individual components that have different functions. The stomach, for example, consists of tissue layers including the surface connective tissue layer, the muscular layer, and the innermost mucosa layer. The researchers also discovered distinct genetic coding guiding the vagal sensory neurons to the different tissue layers. This coding is entirely independent of the genetic coding for organs.

"The researchers also discovered distinct genetic coding guiding the vagal sensory neurons to the different tissue layers. This coding is entirely independent of the genetic coding for organs.

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"'Our second finding is really surprising. No one in previous studies had even considered this," says Chang. "By knowing these two codes, you know precisely where a particular neuron in the vagus nerve projects in the body."

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"'We learned that some neurons in the vagus nerve can respond to lung stretch, others respond to stomach stretch, and others can respond to intestinal nutrient perfusion," says Chang. "For neurons that are designed to detect stretch, for example, it doesn't matter where the stretch happened—it could be from the lung, stomach or small intestine. In other words, neurons with the same 'stretch' code respond to stretches regardless of organs or tissue layers—it's an independent, third dimension."

Comment: the word 'code' is used over and over. Code simply stands for information. This exquisite design was set up in animals when they first appeared with complexity. i think it must have started with the Cambrian organisms. Such automaticity is required for living freely.