The most interesting field in neuroscience right now, to me, is epigenetics - in fact, it might be one of the most important new inquiries we have made in decades into understanding how our biopsychosocial surround impacts our physical health, our mental health, and even our sense of who are as human beings.

From Seminars in Reproductive Medicine: (via NIH)

Epigenetics has been defined and today is generally accepted as ‘‘the study of changes in gene function that are mitotically and/or meiotically heritable and that do not entail a change in DNA sequence.’’[3] The epigenetic modifications described in current literature generally comprise histone variants, posttranslational modifications of amino acids on the amino-terminal tail of histones, and covalent modifications of DNA bases. The validity of the current definition of epigenetics should be seriously questioned because the previously mentioned epigenetic modifications also have a crucial role in the silencing and expression of noncoding sequences.

We know, for example that the nutritional status of a man as he enters puberty will impact the health status of his son (lack of food led to lower-than-normal rates of heart disease, while too much food led to greater risk of diabetes). In animal models (murine), research confirms that "a male mammal’s nutritional past has a surprisingly strong effect on his offspring." Pre-reproduction starvation of male rats produce offspring with lower blood sugar and "altered levels of corticosterone (which protects against stress) and insulin-like growth factor 1 (which helps babies develop)."

In this new study, researchers have re-confirmed prior studies around the impact of pre-conception stress on "behavioral outcomes of offspring, even in adult life, independently of any interactions between the mother and her developing infant."

Maternal Stress Prior to Conception May Influence Genetic Expression of Offspring

November 18, 2013

Stephen I. Deutsch, MD, PhD - Ann Robinson Endowed Chair in Psychiatry, Professor and Chairman, Department of Psychiatry and Behavioral Sciences, Eastern Virginia Medical School; Attending Psychiatrist, Sentara Norfolk General Hospital, Norfolk, Va.

First published in Psychiatry Weekly, Volume 8, Issue 23, November 18, 2013

A recent study showed that maternal pre-reproductive stress in rats occurring before conception and pregnancy had transgenerational effects on both newborn and adult offspring.1 Exposing female adult rats (postnatal day 45-54) to chronic unpredictable stress 14 days before they were mated resulted in increased expression of mRNA for the corticotropin releasing factor type 1 receptor (CRF1) in frontal cortex and mature oocyte of the stressed adult female rats, as well as in the brain of newborn offspring on postnatal day 0.

The data suggest that the transgenerational transmission of effects of pre-reproductive maternal stress occurred via changes in epigenetic regulation of CRF1 expression in ova; there was an 18.5-fold enrichment of CRF1 mRNA expression in mature oocytes of stressed adult female rats, relative to oocytes of controls.1 Changes in epigenetic regulation of gene expression occur commonly as a result of changes in the methylation status of cytosine residues in CpG islands associated with promoter regions of genes. Changes in CRF1 expression may reflect alterations of function in the hypothalamic-pituitary-adrenal (HPA) axis, which responds to stress; also, CRF1 expression is enriched in areas of brain implicated in the stress response (eg, cerebral cortex, hippocampus, and amygdala), as well as in regions of the periphery (eg, GI tract, spleen and ova).

The effects of pre-reproductive maternal stress on behavior of adult offspring were influenced by both gender and the history of stress exposure of the adult offspring, and particularly by the intensity of stressful exposures in adulthood. Also, expression of CRF1 mRNA in brains of adult offspring was influenced by both maternal stress history and the stress history of the adult offspring. Exposure of the adult offspring to high stress, as opposed to low stress, led to the appreciation of differences in regional expression of CRF1 mRNA between adult offspring of maternal pre-reproductive stressed and nonstressed dams. Differences also emerged between male and female adult offspring of stressed dams and their appropriate same-sex controls. Therefore, in the high-stress condition, adult female offspring of maternal pre-reproductive stressed rats showed increased expression of CRF1 mRNA in frontal cortex, compared to adult female control offspring, whereas both male and female adult offspring of maternal pre-reproductive stressed rats showed decreased expression in the amygdala, relative to their same-sex controls.

The implications of this research suggest that the early maternal history before conception and delivery could affect behavioral outcomes of offspring, even in adult life, independently of any interactions between the mother and her developing infant.[1] The transgenerational transmission may occur through the germ line. However, transgenerational effects on outcomes may be influenced by the offspring’s gender and unique developmental history, including history of stressful exposures, and may not be dramatic. Epigenetic transmission may also include transmission of resiliency factors, and plasticity is a feature of the adult brain, so there may be reason to remain optimistic about therapeutic potential.


Disclosure: Dr. Deutsch has received grant support from the Commonwealth Health Research Board (State of Virginia).

Reference:
Zaidan H, Leshem M, Gaisler-Salomon I. (2013, May 31). Prereproductive stress to female rats alters corticotropin releasing factor type 1 expression in ova and behavior and brain corticotropin releasing factor type 1 expression in offspring. Biological Psychiatry;74: 680-687.

* * * * *

Here is the abstract for the original article:

Prereproductive Stress to Female Rats Alters Corticotropin Releasing Factor Type 1 Expression in Ova and Behavior and Brain Corticotropin Releasing Factor Type 1 Expression in Offspring

Hiba Zaidan, Micah Leshem, Inna Gaisler-Salomon

Background

Human and animal studies indicate that vulnerability to stress may be heritable and that changes in germline may mediate some transgenerational effects. Corticotropin releasing factor type 1 (CRF1) is a key component in the stress response. We investigated changes in CRF1 expression in brain and ova of stressed female rats and in the brain of their neonate and adult offspring. Behavioral changes in adulthood were also assessed.

Methods

Adult female rats underwent chronic unpredictable stress. We extracted mature oocytes and brain regions from a subset of rats and mated the rest 2 weeks following the stress procedure. CRF1 expression was assessed using quantitative reverse-transcription polymerase chain reaction. Tests of anxiety and aversive learning were used to examine behavior of offspring in adulthood.

Results

We show that chronic unpredictable stress leads to an increase in CRF1 messenger RNA expression in frontal cortex and mature oocytes. Neonatal offspring of stressed female rats show an increase in brain CRF1 expression. In adulthood, offspring of stressed female rats show sex differences in both CRF1 messenger RNA expression and behavior. Moreover, CRF1 expression patterns in frontal cortex of female offspring depend upon both maternal and individual adverse experience.

Conclusions

Our findings demonstrate that stress affects CRF1 expression in brain but also in ova, pointing to a possible mechanism of transgenerational transmission. In offspring, stress-induced changes are evident at birth and are thus unlikely to result from altered maternal nurturance. Finally, brain CRF1 expression in offspring depends upon gender and upon maternal and individual exposure to adverse environment.

Phillip Longman - Does strong religious belief provide an evolutionary advantage?

My guess, in the cultural current climate, is yes. Fundamentalists have more children, avoid contact with ideas that might create cognitive dissonance with their beliefs, and raise their children to do the same thing.

In fact, according to studies cited in this article, the only group of people whose birthrate is in excess of replacement numbers is the religiously fundamental - they are having bucket loads of kids it seems, while atheists and liberals are having few if any children.

Further, with an intense belief in hell as a reality, not an idea, their faith has an incredibly powerful virus protection against competing memes.

Survival of the Godliest

Does strong religious belief provide an evolutionary advantage?

photo ©2010 Rick T. Wilking

By Phillip Longman

Thursday, November 11, 2010

“Is God Dead?” I was 11 years old I when spotted that still-notorious 1966 Time magazine cover story on my uncle’s coffee table. The news that God was, if not dead, then at least missing, I absorbed with the literalness of a not-yet-quite adolescent. It certainly seemed possible, since I had never seen him, despite much time in church. Nor did God seem involved in world events as I was coming to understand them. No one I knew evoked God’s handiwork to explain the world they saw coming for my generation. As Time quoted Jesuit theologian John Courtney Murray, “The great American proposition is ‘religion is good for the kids, though I'm not religious myself.’” At the end of childhood in a secular age, that seemed about right. God was in the same category as Santa Claus.

Today, of course, God is very much back, in the news at least. Indeed, God is so much back that the so-called New Atheists — Richard Dawkins, Christopher Hitchens, Sam Harris, and others — are furiously writing books denouncing the growing role of religious fundamentalism in world affairs, from inspiring Islamic terrorists to mobilizing “value voters” in the United States. How did this happen?

For secularists, the least upsetting explanation depends on the familiar “forces of reaction” excuse. Too much change, too much freedom, too much bright-light-of-reason affects some people like a virus, causing them to regress into “magical thinking” and or to “cling” to other forms of primitivism. In the Middle East, this narrative insists, rapid urbanization, modernization, alienation created a resurgence of religious fundamentalism. For the growing ranks of the Christian Right, so goes the thought, the “values revolution” set off in the 1960s — feminism, gay rights, self-actualization, multiculturalism — was just too much to bear. They will get over it in time, secularists reassure themselves, and if not, then most of their children will.

Here’s a serious problem with that theory: today’s strongly religious people tend to have a relatively large number of children, whereas secularists increasingly have few, if they have them at all. If you believe in evolution (and what secularist doesn’t?), then you have to take this thoroughly naturalistic explanation for God’s comeback into account.

To be sure, in countries rich and poor, under all forms of government, birth rates are declining across the globe. But they are declining least among those adhering to strict religious codes and literal belief in the Bible, the Torah, or the Koran. Indeed, the pattern of human fertility now fits this pattern: the least likely to procreate are those who profess no believe in God; those who describe themselves as agnostic or simply spiritual are only somewhat slightly less likely to be childless. Moving up the spectrum, family size increases among practicing Unitarians, Reform Jews, mainline Protestants and “cafeteria” Catholics, but the birthrates found in these populations are still far below replacement levels. Only as we approach the realm of religious belief and practice marked by an intensity we might call, for lack of a better word, “fundamentalism,” do we find pockets of high fertility and consequent rapid population growth.

According to a study published in the American Journal of Sociology, three quarters of the growth of conservative Protestantism in the United States is explained by the compounding effect of this population’s higher birth rates over the last century as compared with mainline Protestants. Moreover, the correlation between fundamentalist faith and high fertility continues as we travel still further along the spectrum of religious belief and practice. So, for example, the “Andy Weaver” Amish, who are perhaps the strictest of all in their rejection of modernity, have higher fertility (average 6.2 children per family) than the do the New Order Amish, (4.8 children) who starting in the 1960s made such concessions to progress as allowing electricity into their homes.

Similarly within Israel, ultra-Orthodox Jews, or Haredim, with an average of nearly seven children per family, are far outbreeding merely Orthodox Jews, to say nothing of more secular Israelis. Accordingly, we now find a profound generational difference in Israeli society that reverses the pattern of history that even many religious people once supposed would inevitably lead to the decline of ancient beliefs and customs. Today, just 2.3 percent of Israelis over age 80 are Haredi. But such is the demographic momentum of this sect that 16 percent of all Israeli children under 10 are within its fold.

When confronted with the fact that they are being outbred, secularists often respond that many if not most children born into highly religious families will grow up to reject the faith of their fathers — such is the assumed allure of freedom and individuality. This thought comports with the life experience of the many members of the Baby Boom generation, who shook off the bonds of traditional authority in the 1960s and 1970s, and who cannot imagine why the rest of humanity will not eventually catch on and catch up.

Arguing against this proposition, however, are some stubborn demographic facts. Among fundamentalist families, it turns out, the apple does not fall far from the tree. And the more demanding the faith, the more this rule applies.

Only five percent of children born to the most conservative Amish, for example, move on to other faiths or lifestyles. The defection rate is higher among New Order Amish, Mormons and other comparatively less demanding fundamentalist communities, yet they still hold on to the majority of their children. Moreover, what defections they may experience are more than offset by converts, with the net flow favoring conservative faiths, according to poll data gathered by the National Opinion Research Center at the University of Chicago. Thus we see 21 percent of converts leaving liberal and moderate denominations for more fundamentalist ones, and only 15 percent going the other way. There are many swirls and currents that affect us all as individuals, but between higher fertility and more successful indoctrination, the main demographic tide of history is clearly flowing in favor of fundamentalism.

These and other relevant findings from the sociology of religion come from a powerful new book by Eric Kaufmann entitled Shall the Religious Inherit the Earth?: Demography and Politics in the Twenty-First Century. The book has been released in the United Kingdom, and will be published in the United States next spring. A graduate of Harvard’s Kennedy School of Government who currently teaches at the University of London, Kaufmann provides no faith-based arguments, and doesn’t need them to make his point. Good old-fashioned Darwinism applied empirically to modern conditions will do.

In a world in which childbearing is rarely accidental and almost never rewarding economically, birthrates increasingly reflect values choices. And so, by Darwinian process, those who adhere to traditions that preserve and celebrate the ancient injunction to “go forth and multiply” wind up putting more of their genes and ideas into the future than those who don’t. As Kaufmann shows, fertility, over time, plays out like compound interest. That is, even if religiously fundamentalist families only have a few more children than secular or religiously moderate counterparts, and they can keep those children holding on to fundamentalist faith and values (especially related to child-bearing), the passage of generations will greatly magnify their numbers and influence. Similarly, secularists and others who choose to have only one or two children, and who pass those values on to their children, will, over time, see their population decline precipitously.

Ironically, the structure and sensibility of secular society is bringing about its own demise. By the 1960s, expanding secularism may have set back religion severely as a force in history, but in doing do so, it strengthened the remaining strongholds of faith and set in motion patterns of reproduction and acculturation that would allow its most fundamentalist forms to reclaim the future. Though there may of course be a deeper reason, one need believe no more than this to understand why the God who was missing in my childhood has returned.

Phillip Longman is a senior research fellow at the New America Foundation and Schwartz Senior Fellow at the Washington Monthly. His latest book, co-authored with Ray Boshara, is The Next Progressive Era: A Blueprint for Broad Prosperity.

Tags: Religion, culture, reproduction, Phillip Longman, strong religious belief, evolutionary advantage, Survival of the Godliest, Big Questions Online, fundamentalists, birth rates, secularists, Amish, Eric Kaufmann, Shall the Religious Inherit the Earth?, Demography, Politics, Twenty-First Century