Effects Of Stress And Pollution Passed To Future Generations Through Epigenetic DNA Changes


When the Human Genome Project ended a decade ago, scientists thought that they had closed the lid on all that is to be known about our genes. But what they really did was open a Pandora’s Box, says theoretical evolutionary biologist Prof. Eva Jablonka of Tel Aviv University’s Cohn Institute for the History and Philosophy of Science and Ideas.

After sifting through hundreds of scientific studies concerned with epigenetics, Prof. Jablonka concludes that some of the effects of stress, cancer, and other chronic diseases we suffer from may be passed on to our offspring through deep and complicated underlying cellular mechanisms that we are just now beginning to understand.

Prof. Jablonka will discuss her findings at an epigenetics conference in North Carolina later this month.

The invisible threat
Epigenetic research suggests that the effects of stress and environmental pollution can be passed on to future generations without any obvious change or mutation in our DNA. The problem, Prof. Jablonka points out, is that we have no idea of the extent these effects will have on the human genome of the future.

“I am a story teller. I read a lot of information and develop theories about evolution. For the last 25 years, before it became a fad, I was interested in the transmission of information not dependent on DNA variations,” Dr. Jablonka says. “Epigenetic inheritance is information about us that is not explicitly encoded in our genes. Two individuals may have identical genes, but the genes present very different characteristics. They can be genetically identical but different epigenetically.”

In a 2009 paper for the Quarterly Review of Biology, Prof. Jablonka wrote about cellular epigenetic inheritance and explored some of the consequences of such inheritance for the study of evolution, also pointing to the importance of recognizing and understanding epigenetic inheritance for practical and theoretical issues in biology. She has since concluded that individuals can influence their heredity.

After reviewing the literature, she has found more than 100 examples of living organisms, from bacteria to human beings, demonstrating how our genes’ expression can be altered and inherited.

“Stress is enormously important,” Prof. Jablonka says. “It can affect the development of cancer and other chronic diseases, and may also have long term impacts on ecology.” At the conclusion of the Human Genome Project, researchers hoped that the findings would provide relief from several diseases. “What they weren’t prepared for,” she continues, “is that genes really do so many things, and that gene expression patterns can be heritable. We can learn some things about diseases from our DNA, but it doesn’t tell the whole story.”

Is environmental pollution irreversible?
Stress can create near invisible effects on gene expression, effects that can be passed from mother or father to child. Some of this operates through microRNA, tiny RNA discovered about a decade ago, which work as cellular “micro-managers.” In addition, a process called DNA methylation alters gene function. Various processes “hidden” in chromosomes within the cells appear to be influenced by lifestyle and disease.

As a result, Prof. Jablonka advises that it might be prudent to reconsider all the environmental pollutants being introduced into the planet’s ecosystems. Some pesticides and fungicides are androgen suppressors and have many effects on gene expression — and these effects can be inherited. Whether and how future generations can endure with these altered gene functions are still open questions, she says.

Source The Behavioral Medicine Report

Similarities Found in Brain Activity for Both Habits and Goals

ScienceDaily


A team of researchers has found that pursuing carefully planned goals and engaging in more automatic habits shows overlapping neurological mechanisms. Because the findings, which appear in the latest issue of the journal Neuron, show a neurological linkage between goal-directed and habitual, and perhaps damaging, behaviors, they may offer a pathway for beginning to address addiction and similar maladies.

The study was conducted by researchers at New York University’s Center for Neural Science and Department of Psychology, Princeton University’s Department of Psychology and Neuroscience Institute, and University College London’s Wellcome Trust Centre for Neuroimaging and Gatsby Computational Neuroscience Unit, University College London.

The brain is believed to engage in two types of decision-making processes — deliberative, in which the future consequences of potential actions are weighed in order to achieve a particular goal, and automatic or habitual, in which previously successful actions are repeated without further contemplation. While the mechanisms behind these behaviors are distinct — with goal-directed actions the result of planning and habitual ones, associated with addiction, produced more thoughtlessly — researchers have had difficulty separating them behaviorally as they both typically pursue common ends.

The researchers on the Neuron study sought to differentiate both types of decision making by studying how humans’ decisions and brain activity, measured using functional magnetic resonance imaging (fMRI), were influenced by previously received vs. potential future rewards in a gambling game.

In the experiments, subjects were asked to make two sets of choices, with a monetary reward given if they made certain selections. In the first set of choices, subjects were asked to make selections between different slot machines, represented by colored boxes. These choices led to the opportunity to choose between additional slot machines. If the subjects made certain choices in this second stage, they received a monetary reward. Each subject repeated this process 200 times, with the chance of winning a monetary reward varying in each round — in some rounds, certain selections were associated with a high chance of winning money; in other rounds, these same choices were much less likely to yield a monetary benefit.

By analyzing how subjects adjusted their choices based on winning, or failing to win, money, the researchers were able to distinguish goal-directed from habitual decisions. Since the chances of winning money for different choices were constantly changing, a habitual decision, which is based on repeating a previously rewarded choice, was distinct from a goal directed one, which is based on contemplating the future outcome expected for the action.

Having dissociated the two types of decisions, the researchers examined brain activity related to decision processes. Despite the distinctions between goal-directed and habitual behaviors, the subjects’ brain activity was similar for both types of action. Indeed, signals related to goal-directed plans were observed in an area of the brain known as the ventral striatum, which is normally associated with habits and drug abuse.

“This surprising result shows that the brain’s systems for different behaviors are more intertwined than previously thought,” explained Nathaniel Daw, an assistant professor in NYU’s Center for Neural Science and Department of Psychology, one of the study’s co-authors.

The authors added that the finding paves the way for seeking to understand how the brain regulates between goal-directed and habitual behaviors. By comprehending the mechanisms by which the brain controls these behaviors, subsequent research can begin to address how to curb habitual behaviors such as drug addiction or alcoholism. More specifically, because these decisions have a common neural target, there is a possibility that therapeutic methods could be designed and tested, targeting this locus, to enhance goal-directed behaviors while diminishing habitual ones.

The study was funded, in part, by a grant from the National Institute of Mental Health.

Source ScienceDaily

How to feel good – or at least stop feeling bad

By Dr. Leslie Becker-Phelps


If only we could wish away bad habits and unwanted traits. We would all be like the population of Garrison Keillor’s Lake Wobegon – “where all the women are strong, all the men are good looking, and all the children are above average.” Instead, we are stuck with our imperfect selves. While we enjoy shining moments of accomplishment and virtue, we also struggle with the less stellar aspects of ourselves; such as unhealthy eating, low self-esteem, depression, or untold anxieties.

Part of being human is the experience of always being a work in progress – never that final, perfect person. This can make life an exciting adventure; as long as you continue to move in the direction of growth.

Two important steps in encouraging growth are really being ‘in’ your life experiences – not always thinking about other things – and accepting those experiences. When you acknowledge, experience, and fully accept your feelings, you are essentially accepting all aspects of yourself and gaining a sense of being ‘at home’ in you. Even when you don’t like your emotions or are unhappy, they can still feel right. A perfect example of this is when you grieve the loss of someone important in your life; you don’t like the experience, but you have a sense that it is a genuine expression of your feelings, and so it feels right.

You might be thinking; This all sound great, but how can I find such inner peace? There is one very good way to do this that I am hesitant to mention because so many people misunderstand it… meditation. Although increasingly more people are learning the benefits of it for themselves, there are also many others who immediately ‘know’ it is not for them. They might be right, but they dismiss it before they really even understand it.

People often think of meditation as achieving a state of bliss, or at least a deep calm. Although it’s true that meditation can be relaxing, that’s not its main purpose. It is a practice of being aware of, and directing, your attention to your moment-by-moment experience. And it does this by teaching people to see when they become distracted or carried away with thoughts or feelings; and to return their attention to the moment (often focusing on their breath).

This process can be applied to people’s lives outside of meditation, helping them to change things about themselves. So, for example, the emotional overeater can note her urges to eat; learn to tolerate them – along with any accompanying unpleasant emotions – without reaching for food; and return her attention the tasks at hand in her daily routine. Importantly, she is neither denying her urges, which might send them underground to sabotage her later; nor chastising herself for having them, which would undermine her motivation to treat herself well and make healthier food choices.

Stated succinctly, meditation helps people change by teaching them to be inside their experience and simultaneously outside, watching it with perspective. By being in the moment without feeling overcome by emotion, people can become adept at seeing themselves repeat patterns. Then, while acknowledging and experiencing an old pattern, they can choose to respond differently. It’s in this way that meditation frees people to make the personal changes they so desire.

Source Psychology Today

Stress Affects The Balance Of Bacteria In The Gut And Immune Response

By Christopher Fisher, PhD


Stress can change the balance of bacteria that naturally live in the gut, according to research published this month in the journal Brain, Behavior, and Immunity. Exposure to stress led to changes in composition, diversity and number of gut microorganisms, according to scientists from The Ohio State University. The bacterial communities in the intestine became less diverse, and had greater numbers of potentially harmful bacteria, such as Clostridium.

“These bacteria affect immune function, and may help explain why stress dysregulates the immune response,” said lead researcher Michael Bailey.

“These changes can have profound implications for physiological function,” explained Dr Bailey. “When we reduced the number of bacteria in the intestines using antibiotics, we found that some of the effects of stress on the immune system were prevented”, he added. “This suggests that not only does stress change the bacteria levels in the gut, but that these alterations can, in turn, impact our immunity.”

“This is the first evidence that the gut microorganisms may play a role in innate immunological stress responses,” said Monika Fleshner, Professor of Integrative Physiology at the University of Colorado, Boulder. “The study reveals the dynamic interactions between multiple physiological systems including the intestinal microbiota and the immune system.”

Because gut bacteria have been linked to diseases like inflammatory bowel disease, and even to asthma, a future goal of the study is to determine whether alterations of gut bacteria is the reason why these diseases tend to be worse during periods of pressure.

The research was conducted with colleagues from the Texas Tech University Health Sciences Center and the Research and Testing Laboratories, and was funded by the National Institute of Health.

Source The Behavioral Medicine Report

Organic Mind

By Dean F. MacKinnon, M.D.


Medicine can sometimes be a lot like auto mechanics. If you listen to master mechanics like the guys on Car Talk, you can almost hear the wheels turn as they ask probing questions to narrow the possible explanations of the caller’s car problem to a narrow differential diagnosis and, often by this application of pure reason and experience, the solution to the problem. It is the same kind of reasoning process, albeit a million times funnier, that you would hear if you could listen in on a doctor’s ruminations about a patient’s illness.

You might doubt that we are able to apply this kind of thinking to the mind, but I propose that you can think mechanistically about mind if you focus not on the parts, but on what they do; that is, on their function. In this sense, mind is the organic function of the brain, the way circulation is the function of the organ we call the heart. Whereas the heart pumps, the mind is there, fundamentally, to enhance our acquisition and use of energy from the environment.

All living organisms depend on energy to survive. It stands to reason, then, that a well adapted organism is one that can acquire energy reliably. Simpler organisms do so by trial and error, which may be a successful approach for a species, but a raw deal for the individual organism that gets caught without resources in a hostile environment.  

The more highly developed the organism, the more wasteful is a trial and error approach to individual survival. Complex organisms have evolved means to detect sources of stored energy in the environment. The brain helps the organism to detect and acquire energy, and to retain information about how to obtain it in the future.

A brain, being highly organized, requires a huge investment of energy. Therefore most creatures with brains also have evolved the capacity to defend themselves from harm. Brainy creatures that communicate and cooperate with one another have additional advantages. Ants secrete pheromones and bees dance to inform colony members and hive mates where to find food sources. We humans can condense our own internal experiences–perceptions, thoughts, feelings, intentions, memories, beliefs–into time- and energy-efficient signs and symbols. We can pass along to others not only information about sources of energy and danger, but also precise information about the qualities of the objects we have encountered.

The ability to communicate about internal states and the qualities of objects has contributed to the development of social cooperation. We can tell others what we need and learn what they need. Information about thoughts, feelings, and intentions also adds depth to information about the world. When we communicate our subjective reflections on the objective world we provide richer and more nuanced information, and reduce trial and error for others. Symbolic communication–language–has made it possible to transmit information over time and space, so that people we never even meet help us survive and prosper from the experiences they had long ago and far away.

A brain allows an organism to adapt its actions to its environment; it optimizes the search for energy and defends its adaptations. A brain that is equipped to communicate and cooperate with others optimizes resources and defense for others, and gains in return. A brain that can detect, retain, recall, and communicate efficiently about remote and internal events uses a special set of functions that occur abundantly only in humans, and partially in only a few other mammals: these are called mental functions, or mind. When we describe someone as “mentally ill” or “out of her or his mind” or behaving “mindlessly,” we mean that the person’s problem is abnormal or inappropriate or inadequate or painful or erroneous thoughts, feelings, and intentional actions.

Source Psychology Today