Dr. Diego Bohórquez

And so he named the diffuse endocrine system of the gut, and then he came up with this word enteroendocrine cell.

And these cells are dispersed at a ratio, roughly speaking, like 1 to 1,000 epithelial cells throughout the digestive tract.

And we thought for the longest time that these cells were not connecting directly to the nervous system, that they will release these neuromodulators and the neuromodulators through diffusion will act on receptors into some of the nerve terminals.

And that is true.

That is a very well-established system.

But in 2015, we made an observation that some of these cells

anywhere from one-third to two-thirds of these cells, it depends on the type of systems that you use to identify it, they were contacting directly the nervous system.

And that brought up a new dimension of how it is that the gut could be communicating

to the brain, because as you know, in the brain, the synapses are the ones that are most predominant.

However, there is a lot of neuromodulation from endocrine functions in the brain too.

So in the gut, this was not well described.

There had been historically a few examples that these cells may be making synaptic contacts, but they had not been studied.

And perhaps one of the main reasons why they hadn't been studied is because the tools were not there.

And if you recall in the...

In 1990s, with the advancement of green fluorescence protein as one of the main molecules to tag cells, now all of a sudden there was a revolution in biology because you could identify the cells, you can take them out, you can do a transcriptomic analysis to see what genes they express.

You could co-culture them, you can modify their genome, and then you can start to interrogate what is their contribution to the entire body.

Correct.

Maybe here is fitting how it is that I got into studying this system.

As you know, between the 90s and the early 2000s, there was an explosion in tools to study the brain and neural circuitry and the connection of neurons and each one of the neurons.

Because up until the 1990s, the tools were limited, electrophysiology, behavior.