The Secret Language of Cells: What Biological Conversations Tell Us About the Brain-Body Connection, the Future of Medicine, and Life Itself!

Introduction

The greatest secret of modern biological science, hiding in plain sight, is that all of life’s activity occurs because of conversations among cells. During infections, immune T cells tell brain cells that we should “feel sick” and lie down. Long-distance signals direct white blood cells at every step of their long journey to an infection. Cancer cells warn their community about immune and microbe attacks. Gut cells talk with microbes to determine who are friends and enemies. Instructor cells in the thymus teach T cells not to destroy human tissues.

This key to modern medical science is hidden because it is impossible for most of us to understand the best current technical journals in neuroscience, genetics, molecular biology, immunology, and microbiology. Filled with incomprehensible names of molecules, signals, receptors, and cells, the secret of cellular communication is concealed by jargon.

Understanding the Conversations

Taking away the mystery, The Secret Language of Cells provides a clear way to understand medical research— and life itself. Explained in everyday English, the many languages of cells and how they operate are laid bare. Sections of this book focus on cells from the body, the brain, microbes, and communication inside cells between cell compartments. By describing the lifestyle of each cell, Secret Language makes advanced biology understandable.

And whether you speak jargon or not, The Secret Language of Cells will make clear the extent and significance of this pervasive communication. Perhaps, like me, you will gain a greater sense of awe about the nature of cell signaling, which we are just beginning to tap into, and how it influences the life of every organism on the planet.

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The overwhelming conclusion of the best current research is that all processes in the human body, in all animals and plants, and in microbe communities as well, are based on conversations and group decision making among cells. By understanding how determinations are made among a wide range of cells from the immune system, blood vessels, barrier cells of the gut and skin, brain tissue, and microbes, it becomes clear how cellular communication determines health and disease.

In fact, understanding cellular communication will allow you to keep up with the latest, most advanced modern medical treatments—such as new immune therapies for cancer. Experimental treatments using microbes and immune cells against any number of cancers take advantage of natural conversations among these cells. Elaborate discussions in the gut determine how microbes might affect treatments related to metabolism, weight loss, anxiety, gut diseases, food allergies, and brain diseases. Results of cellular conversations between immune cells and brain cells determine possible treatments for stress, inflammation, depression, anxiety, trauma, brain disease, and microbe invasions.

Same Language, Different Approaches

Chapters in The Secret Language of Cells demonstrate the many different cells that use multiple signals at the same time. All of the following can serve as signaling devices:

secreted chemicals

launched sacs filled with genetic instructions

electric currents

electromagnetic waves

physical contact by cells

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• biological nanotubes between cells
Remarkably, all levels of cells throughout nature—humans, animals, plants, and

microbes—use these same languages with the same vocabulary.
You are likely aware that neurons use one type of signal in brain circuits. Neurons

produce electrical currents along an axon, which triggers release of neurotransmitter molecules as a signal to another neuron. In fact, neurons use all of these other language techniques just mentioned—and at the same time. Neurons don’t just talk with other neurons; they talk with three other types of supportive brain cells, multiple immune cells, and cells from all other human tissues—simultaneously. In chronic pain syndromes, neurons communicate through complex connections, sometimes including ten different cell types at once. Another recently discovered neuron trick is sending messages to local immune cells sideways from the axon into the tissue, rather than at the usual connection to the next neuron in a circuit.

Neurons also communicate with brain waves. Groups of neurons vibrate together, sending particular frequencies of electromagnetic oscillations as messages to other brain regions. For messages between two primary brain memory centers, one frequency provides spatial information about the memory, and a different frequency supplies time-related information.

The science of cell signaling demonstrates that the immune system and the brain can’t really be separated. Both perceive stress, social isolation, trauma, and infections and talk together constantly about all of these. The brain is built on a dynamic, but fairly fixed, structure of circuits. This “wired” brain sends signals rapidly to particular locations throughout the body. Immune cells, on the other hand, travel freely throughout tissue and blood, constantly signaling to each other, to brain cells, and to bodily organs. This “wireless brain” can send signals through blood and tissue to other locations that are hard to reach.

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By reading The Secret Language of Cells, you will understand how the wired and wireless brains work constantly together through wide-ranging conversations. This type of communication between mobile immune cells and stationary nerves is described in the book as a way to explain the wide-ranging effects of acupuncture.

Another example of the brain and immune system working together occurs when the master immune regulator T cell travels into the fluid that bathes the brain. From that vantage point, T cells send signals to brain cells explaining whether there is an infection or not. Signals from these immune T cells normally stimulate ordinary cognition. When an infection occurs, T cells alter their signals to trigger “the sick feeling” we all experience when ill. They tell the brain it is time to slow down and rest so that healing can occur.

Understanding the Basis of Health and Disease

The Secret Language of Cells puts together and organizes a large amount of information not available in one place anywhere else. Based on the latest findings from the top scientific journals, it is a modern view of biological science whose time has come. As medical science becomes increasingly complex, many people find it more challenging than ever to understand what maintains health and what causes disease.

Each chapter of The Secret Language of Cells provides insight into critical new areas of immunity, cancer, and the physiology of the brain, gut, and skin. Anyone interested in microbes; how the body and brain work; how immune, blood, and gut cells work; and how cancer works will find this book essential reading.

By following stories of each major cell type, you will understand these conversations firsthand. Cells that provide a border for an organ might seem to be boring, but in fact, lining

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cells in the gut have elaborate conversations and make many of the most important decisions. Large numbers of microbes in the gut talk to these barrier cells, as well as immune cells, local neurons, and each other. All through the long gut, these conversations determine which specific microbes are allowed to live as residents to help us in many different ways.

The lining cells of skin, lung, blood vessels, and brain fluid are also engaged in conversations with cells from every other part of the body. In the brain, gatekeeper cells determine which specific cells can enter the brain and which are needed to heal brain trauma and infections. Surprisingly, capillary lining cells not only line the smallest blood vessels but also have major roles in instructing each organ how to produce cells to build tissues. Special cells in each organ that produce all other cells are called stem cells, and they sit right next to capillaries. Both capillary cells and stem cells engage in back-and-forth conversations about how to supply new cells for the tissue as needed.

Daily Conversations and the Question of Intelligence

The Secret Language of Cells describes multiple kinds of cellular conversations. Cells talk about every aspect of life—where they should be in an organ, what time of day activity must occur, how big they should grow, how they can fight microbes together, how to rebuild and heal tissue, and how to cooperate to provide necessary functions for our daily activity. Conversations determine types of inflammation, how food is digested, and chronic pain. Almost every aspect of physiology is determined by back-and-forth signaling among groups of cells. Often, the discussion group is large and includes blood cells, tissue lining cells, immune cells, and brain cells, all at the same time. Microbes and cancer cells take part as well.

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Conversations also occur between small components inside cells. These organelles are tiny parts of cells, just as organs are smaller parts of the body. Signals are sent between organelles, such as mitochondria and the nucleus. Some complex molecules appear to send signals as well—gathering data, making decisions, and signaling back-and-forth with organelles. Signals inside cells between organelles and molecules are much harder for scientists to observe, and these conversations are just now being discovered.

Are cellular conversations “intelligent”? Since no one can really define intelligence in nature, it is not possible to answer this question. Certainly, lifestyles of cells are complex and intriguing. Cells use back-and-forth discussions to ask questions, get answers, give feedback, gather information, call for each other, move through the body, and make decisions based on multiple inputs. Signals stimulate very specific actions, which are altered as situations change. The question about the implications of ubiquitous cellular communication explaining intelligence in nature is discussed in the concluding chapter.

The Blog and Realization

The central place of cellular signaling in nature dawned on me gradually. For forty years as a neuropsychiatrist, I witnessed the interactions of medical and mental events—effects of medical conditions on the brain and the actions of mind on the body. After extensive research, it became apparent that no one could say what the mind is or where it could be in the brain. This led to the question of where mind, or intelligence, might reside in nature.

Eight years ago, I began an exploration of mind in nature through my website, Searching for the Mind with Jon Lieff, M.D. Presenting detailed blog posts on the website each week was the best way for me to keep up with the most current scientific information and receive

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immediate feedback from readers. Daily interactions with many readers increased with a Facebook page (Searching for the Mind) and a Twitter account—@jonlieffmd. A large community of people, including top scientists, joined me in attempting to find where intelligence might be in nature.

Multiple blog posts considered remarkable functions of the human brain. Because of these, I was asked to write two guest blog posts for Scientific American about the close relationship of the wired and wireless brains and the creation of new cells in the adult brain. Other blog posts described amazing capacities in other animals’ brains—even the tiniest. For example, bees have the ability to retain kaleidoscopic memories of five miles of travel, use abstract concepts and symbolic language, and intelligently self-medicate. Another honor occurred when a top animal scientist, Marc Bekoff, asked me to write a joint guest post on his blog for Psychology Today. The article described unique types of intelligence in birds, lizards, and bees, whose brains are all quite different from humans’.

In all of these different brains, the same types of vital conversations occur among cells, but in different patterns. Similar cellular conversations are also found in plants talking with microbes to build nitrogen factors. One of the most intriguing plant discoveries in the new science of cellular communication is that almost all trees and shrubs in a forest are connected by conversations sent along long, microscopic threads of fungus cells, which function as wires. Through this internet of fungal wires, trees and other plants send signals to nourish and defend each other.

Perhaps most remarkable of all is communication among microbes. Unicellular microbes display unusual abilities for single-celled creatures, almost as if they have a brain. Somehow, they are able to make decisions from multiple simultaneous inputs. They demonstrate elaborate

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back-and-forth communication with each other, but, even more surprisingly, with much larger and more complex human cells.

Synthesizing and writing about the most current research from the best scientific journals led me to the startling conclusion that cellular communication is the basis of all current medical science, and of life itself. Everywhere we look, cells are talking to each other. This includes blood cells, immune cells, gut cells, brain cells, plant cells, and all microbes—even viruses, which some scientists don’t classify as being alive. It became apparent to me that signaling among cells is the way biology works.

I noticed that an overarching synthesis of conversations among cells is nowhere to be found in any books or journal articles. The time had come to put forth this thesis and the overwhelming evidence—hence The Secret Language of Cells. It synthesizes eight years of intensive analysis of the scientific literature and makes research understandable for the general science reader.

As science progresses, more and more detailed information becomes available—with a greater ability to observe smaller and smaller events in nature. Just recently, it has become possible to observe the specific conversations among cells. Even more recently, the first signals sent between viruses have been observed.

Cellular Viewpoints

The Secret Language of Cells is divided into four sections. Each section can be read by itself. However, reading all sections gives a deeper understanding of the interrelationships of all the cells and how physiology works in health and disease.

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The first section is about cells in the body—T cells, capillary cells lining the smallest blood vessels, traveling blood cells, platelets, gut cells, skin cells, and cancer cells. While each organ is unique and fascinating, the particular cells in this section are chosen as important examples that give insight into how all organs operate through cell communication.

The second section is about the brain—neurons, three types of supportive brain cells, two types of guardian barrier cells protecting the brain, and a chapter on the unique conversations that produce various chronic pain syndromes. The third section describes the world of microbe communication—among microbe species, with plants, and with humans.

A fourth section explains conversations inside cells—among organelles and other cellular components, such as mitochondria and protein factories. Section four also includes the description of a molecule that appears to send signals to these components. The conclusion begins to grapple with the implications of these ubiquitous cellular conversations.

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Section I The Body

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Chapter 1
Cells—They Talk About Everything!

Cellular communication is inherently complicated, with an immeasurable number of signals going in all directions at once. In the midst of billions of cells, a particular cell can rapidly make complex decisions and send signals that direct the efforts of many other cells to make our bodies work in amazing ways.

Before we delve into how specific types of cells—blood cells, gut and skin cells, cancer cells, brain cells, microbes, and more—use signals to perform their unique physiological functions, we’ll devote this chapter to discussing four areas that all cells appear to converse about, which was once unfathomable to even the most ardent researchers. These cellular conversations allow each cell to function with other cells in tissue throughout the body by knowing their appropriate size, their age, the time of day, and their own location.

While it is clear that individual cells are able to use the information that is described throughout this chapter in a variety of important ways, the mechanisms by which they do so are just now beginning to be discovered, and there is still much to learn. Finding individual minuscule molecules used as signals inside cells and tissues is extremely difficult, even as advanced imaging technologies are enabling us to view ever smaller details of cells. In further chapters, it will be seen that more detailed information is becoming available for many of the cells described.

Determining Their Proper Size

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