Anterior cingulate cortex

A review of fetal adverse events

gettingwell4 2-3 stars Required further work, Amygdala, Anterior cingulate cortex, Brain development, Cerebellum, Cerebrum, Cortisol, Epigenetics, Glutamate, Hippocampus, Hypothalamus, Immune system, Limbic system, Lower brain, Memory, Neurochemicals, Stress , , , , , , ,

This 2019 Australian review subject was fetal adversities:

“Adversity during the perinatal period is a significant risk factor for the development of neurodevelopmental disorders long after the causative event. Despite stemming from a variety of causes, perinatal compromise appears to have similar effects on the developing brain, thereby resulting in behavioural disorders of a similar nature.

These behavioural disorders occur in a sex‐dependent manner, with males affected more by externalizing behaviours such as attention deficit hyperactivity disorder (ADHD) and females by internalizing behaviours such as anxiety. The term ‘perinatal compromise’ serves as an umbrella term for intrauterine growth restriction, maternal immune activation, prenatal stress, early life stress, premature birth, placental dysfunction, and perinatal hypoxia.

The above conditions are associated with imbalanced excitatory-inhibitory pathways resulting from reduced GABAergic signalling. Methylation of the GAD1/GAD67 gene, which encodes the key glutamate‐to‐GABA synthesizing enzyme Glutamate Decarboxylase 1, resulting in increased levels of glutamate is one epigenetic mechanism that may account for a tendency towards excitation in disorders such as ADHD.

The posterior cerebellum’s role in higher executive functioning is becoming well established due to its connections with the prefrontal cortex, association cortices, and limbic system. It is now suggested that disruptions to cerebellar development, which can occur due to late gestation compromises such as preterm birth, can have a major impact on the region of the brain to which it projects.

Activation of the maternal hypothalamic-pituitary adrenal (HPA) axis and placental protection. Psychological stress is perceived by the maternal HPA axis, which stimulates cortisol release from the maternal adrenal gland.

High levels of maternal cortisol are normally prevented from reaching the fetus by the 11β-hydroxysteroid dehydrogenase 2 (HSD11B2) enzyme, which converts cortisol to the much less active cortisone. Under conditions of high maternal stress, this protective mechanism can be overwhelmed, with the gene encoding the enzyme becoming methylated, which reduces its expression allowing cortisol to cross the placenta and reach the fetus.”

The reviewers extrapolated many animal study findings to humans, although most of their own work was with guinea pigs. The “suggest” and “may” qualifiers were used often – 22 and 37 times, respectively. More frequent use of the “appears,” “hypothesize,” “propose,” and “possible” terms was justified.

As a result, many reviewed items such as the above graphic and caption should be viewed as hypothetical for humans rather than reflecting solid evidence from quality human studies.

The reviewers focused on the prenatal (before birth) period more than the perinatal (last trimester of pregnancy to one month after birth) period. There were fewer mentions of birth and early infancy adversities.

https://onlinelibrary.wiley.com/doi/abs/10.1111/jne.12814 “Perinatal compromise contributes to programming of GABAergic and Glutamatergic systems leading to long-term effects on offspring behaviour” (not freely available)

A mid-year selection of epigenetic topics

gettingwell4 4-5 stars Advanced knowledge, Acetylcholine, Amygdala, Anterior cingulate cortex, Beliefs, Brain development, Brainstem, Cerebellum, Cerebrum, Cortisol, Dopamine, Epigenetics, Glutamate, Hippocampus, Hypothalamus, Immune system, Limbic system, Lower brain, Memory, Neurochemicals, Primal Therapy, Serotonin, Stress, Telomeres, Testosterone, Vasopressin , , , , , , , , , , , , , , , , , ,

Here are the most popular of the 65 posts I’ve made so far in 2018, starting from the earliest:

The pain societies instill into children

DNA methylation and childhood adversity

Epigenetic mechanisms of muscle memory

Sex-specific impacts of childhood trauma

Sleep and adult brain neurogenesis

This dietary supplement is better for depression symptoms than placebo

The epigenetic clock theory of aging

A flying human tethered to a monkey

Immune memory in the brain

The lack of oxygen’s epigenetic effects on a fetus

Resiliency in stress responses

gettingwell4 < 0 Detracted from science, Amygdala, Anterior cingulate cortex, Beliefs, Brain development, Brainstem, Cerebrum, Cortisol, Dopamine, Epigenetics, Glutamate, Hippocampus, Hypothalamus, Limbic system, Locus coeruleus, Lower brain, Memory, Neurochemicals, Oxytocin, Primal Therapy, Serotonin, Stress, Thalamus , , , , , , , , ,

This 2018 US Veterans Administration review subject was resiliency and stress responses:

“Neurobiological and behavioral responses to stress are highly variable. Exposure to a similar stressor can lead to heterogeneous outcomes — manifesting psychopathology in one individual, but having minimal effect, or even enhancing resilience, in another.

We highlight aspects of stress response modulation related to early life development and epigenetics, selected neurobiological and neurochemical systems, and a number of emotional, cognitive, psychosocial, and behavioral factors important in resilience.”

The review cited studies I’ve previously curated:

There were two things I didn’t understand about this review. The first was why the paper isn’t freely available. It’s completely paid for by the US taxpayer, and no copyright is claimed. I recommend contacting the authors for a copy.

The second was why the VA hasn’t participated in either animal or human follow-on studies to the 2015 Northwestern University GABAergic mechanisms regulated by miR-33 encode state-dependent fear. That study’s relevance to PTSD, this review’s subject, and the VA’s mission is too important to ignore. For example:

“Fear-inducing memories can be state dependent, meaning that they can best be retrieved if the brain states at encoding and retrieval are similar.

“It’s difficult for therapists to help these patients,” Radulovic said, “because the patients themselves can’t remember their traumatic experiences that are the root cause of their symptoms.”

The findings imply that in response to traumatic stress, some individuals, instead of activating the glutamate system to store memories, activate the extra-synaptic GABA system and form inaccessible traumatic memories.”

I curated the research in A study that provided evidence for basic principles of Primal Therapy. These researchers have published several papers since then. Here are the abstracts from three of them:

Experimental Methods for Functional Studies of microRNAs in Animal Models of Psychiatric Disorders

“Pharmacological treatments for psychiatric illnesses are often unsuccessful. This is largely due to the poor understanding of the molecular mechanisms underlying these disorders. We are particularly interested in elucidating the mechanism of affective disorders rooted in traumatic experiences.

To date, the research of mental disorders in general has focused on the causal role of individual genes and proteins, an approach that is inconsistent with the proposed polygenetic nature of these disorders. We recently took an alternative direction, by establishing the role of miRNAs in the coding of stress-related, fear-provoking memories.

Here we describe in detail our work on the role of miR-33 in state-dependent learning, a process implicated in dissociative amnesia, wherein memories formed in a certain brain state can best be retrieved if the brain is in the same state. We present the specific experimental approaches we apply to study the role of miRNAs in this model and demonstrate that miR-33 regulates the susceptibility to state-dependent learning induced by inhibitory neurotransmission.”

Neurobiological mechanisms of state-dependent learning

“State-dependent learning (SDL) is a phenomenon relating to information storage and retrieval restricted to discrete states. While extensively studied using psychopharmacological approaches, SDL has not been subjected to rigorous neuroscientific study.

Here we present an overview of approaches historically used to induce SDL, and highlight some of the known neurobiological mechanisms, in particular those related to inhibitory neurotransmission and its regulation by microRNAs (miR).

We also propose novel cellular and circuit mechanisms as contributing factors. Lastly, we discuss the implications of advancing our knowledge on SDL, both for most fundamental processes of learning and memory as well as for development and maintenance of psychopathology.”

Neurobiological correlates of state-dependent context fear

“Retrieval of fear memories can be state-dependent, meaning that they are best retrieved if the brain states at encoding and retrieval are similar. Such states can be induced by activating extrasynaptic γ-aminobutyric acid type A receptors (GABAAR) with the broad α-subunit activator gaboxadol. However, the circuit mechanisms and specific subunits underlying gaboxadol’s effects are not well understood.

Here we show that gaboxadol induces profound changes of local and network oscillatory activity, indicative of discoordinated hippocampal-cortical activity, that were accompanied by robust and long-lasting state-dependent conditioned fear. Episodic memories typically are hippocampus-dependent for a limited period after learning, but become cortex-dependent with the passage of time.

In contrast, state-dependent memories continued to rely on hippocampal GABAergic mechanisms for memory retrieval. Pharmacological approaches with α- subunit-specific agonists targeting the hippocampus implicated the prototypic extrasynaptic subunits (α4) as the mediator of state-dependent conditioned fear.

Together, our findings suggest that continued dependence on hippocampal rather than cortical mechanisms could be an important feature of state-dependent memories that contributes to their conditional retrieval.”

Here’s an independent 2017 Netherlands/UC San Diego review that should bring these researchers’ efforts to the VA’s attention:

MicroRNAs in Post-traumatic Stress Disorder

“Post-traumatic stress disorder (PTSD) is a psychiatric disorder that can develop following exposure to or witnessing of a (potentially) threatening event. A critical issue is to pinpoint the (neuro)biological mechanisms underlying the susceptibility to stress-related disorder such as PTSD, which develops in the minority of ~15% of individuals exposed to trauma.

Over the last few years, a first wave of epigenetic studies has been performed in an attempt to identify the molecular underpinnings of the long-lasting behavioral and mental effects of trauma exposure. The potential roles of non-coding RNAs (ncRNAs) such as microRNAs (miRNAs) in moderating or mediating the impact of severe stress and trauma are increasingly gaining attention. To date, most studies focusing on the roles of miRNAs in PTSD have, however, been completed in animals, using cross-sectional study designs and focusing almost exclusively on subjects with susceptible phenotypes.

Therefore, there is a strong need for new research comprising translational and cross-species approaches that use longitudinal designs for studying trajectories of change contrasting susceptible and resilient subjects. The present review offers a comprehensive overview of available studies of miRNAs in PTSD and discusses the current challenges, pitfalls, and future perspectives of this field.”

Here’s a 2017 Netherlands human study that similarly merits the US Veterans Administration’s attention:

Circulating miRNA associated with posttraumatic stress disorder in a cohort of military combat veterans

“Posttraumatic stress disorder (PTSD) affects many returning combat veterans, but underlying biological mechanisms remain unclear. In order to compare circulating micro RNA (miRNA) of combat veterans with and without PTSD, peripheral blood from 24 subjects was collected following deployment, and isolated miRNA was sequenced.

PTSD was associated with 8 differentially expressed miRNA. Pathway analysis shows that PTSD is related to the axon guidance and Wnt signaling pathways, which work together to support neuronal development through regulation of growth cones. PTSD is associated with miRNAs that regulate biological functions including neuronal activities, suggesting that they play a role in PTSD symptomatology.”

See the below comments for reasons why I downgraded this review’s rating.

https://link.springer.com/article/10.1007/s11920-018-0887-x “Stress Response Modulation Underlying the Psychobiology of Resilience” (not freely available)

Sleep and adult brain neurogenesis

gettingwell4 < 0 Detracted from science, Amygdala, Anterior cingulate cortex, Brain development, Cerebrum, Epigenetics, Hippocampus, Hypothalamus, Limbic system, Memory, Stress , , , ,

This 2018 Japan/Detroit review subject was the impact of sleep and epigenetic modifications on adult dentate gyrus neurogenesis:

“We discuss the functions of adult‐born DG neurons, describe the epigenetic regulation of adult DG neurogenesis, identify overlaps in how sleep and epigenetic modifications impact adult DG neurogenesis and memory consolidation..

Whereas the rate of DG neurogenesis declines exponentially with age in most mammals, humans appear to exhibit a more modest age‐related reduction in DG neurogenesis. Evidence of adult neurogenesis has also been observed in other regions of the mammalian brain such as the subventricular zone, neocortex, hypothalamus, amygdala, and striatum.

Adult‐born DG neurons functionally integrate into hippocampal circuitry and play a special role in cognition during a period of heightened excitability and synaptic plasticity occurring 4–6 weeks after mitosis. Adult DG neurogenesis is regulated by a myriad of intrinsic and extrinsic factors, including:

  • drugs,
  • diet,
  • inflammation,
  • physical activity,
  • environmental enrichment,
  • stress, and
  • trauma.”

Some of what the review stated was contradicted by other evidence. For example, arguments for sleep were based on the memory consolidation paradigm, but evidence against memory consolidation wasn’t cited for balanced consideration.

It reminded me of A review that inadvertently showed how memory paradigms prevented relevant research. That review’s citations included a study led by one of those reviewers where:

“The researchers elected to pursue a workaround of the memory reconsolidation paradigm when the need for a new paradigm of enduring memories directly confronted them!”

Some of what this review stated was speculation. I didn’t quote any sections after:

 “We go one step further and propose..”

The review also had a narrative directed toward:

“Employing sleep interventions and epigenetic drugs..”

It’s storytelling rather than pursuing the scientific method when reviewers approach a topic as these reviewers did.

Instead of reading a directed narrative, read this informative blog post from a Canadian researcher. The post provided scientific contexts to summarize what was and wasn’t known in 2018 about human neurogenesis.

http://onlinelibrary.wiley.com/doi/10.1002/stem.2815/epdf “Regulatory Influence of Sleep and Epigenetics on Adult Hippocampal Neurogenesis and Cognitive and Emotional Function”

Sex-specific impacts of childhood trauma

gettingwell4 4-5 stars Advanced knowledge, Amygdala, Anterior cingulate cortex, Cerebrum, Cortisol, Dopamine, Epigenetics, Hippocampus, Hypothalamus, Limbic system, Memory, Neurochemicals, Serotonin, Stress, Telomeres, Testosterone , , , , ,

This 2018 Canadian paper reviewed evidence for potential sex-specific differences in the lasting impacts of childhood trauma:

“This paper will provide a contextualized summary of neuroendocrine, neuroimaging, and behavioral epigenetic studies on biological sex differences contributing to internalizing psychopathology, specifically posttraumatic stress disorder and depression, among adults with a history of childhood abuse.

Given the breadth of this review, we limit our definition [of] trauma to intentional and interpersonal experiences (i.e., childhood abuse and neglect) in childhood. Psychopathological outcomes within this review will be limited to commonly explored internalizing disorders, specifically PTSD and depression.

Despite the inconsistent and limited findings in this review, a critical future consideration will be whether the biological effects of early life stress can be reversed in the face of evidence-based behavioral interventions, and furthermore, whether these changes may relate to potentially concurrent reductions in susceptibility to negative mental health outcomes.”

It was refreshing to read a paper where the reviewers often interrupted the reader’s train of thought to interject contradictory evidence, and display the scientific method. For example, immediately after citing a trio of well-respected studies that found:

“Psychobiological research on relationships linking impaired HPA axis functioning and adult internalizing disorders are suggestive of lower basal and afternoon levels of plasma cortisol in PTSD phenotype.”

the reviewers stated:

“However, a recent meta-analysis suggests no association between basal cortisol with PTSD.”

and effectively ended the cortisol discussion with:

“Findings are dependent upon variance in extenuating factors, including but not limited to, different measurements of:

  • early adversity,
  • age of onset,
  • basal cortisol levels, as well as
  • trauma forms and subtypes, and
  • presence and severity of psychopathology symptomology.”

The reviewers also provided good summaries of aspects of the reviewed subject. For example, the “Serotonergic system genetic research, childhood trauma and risk of psychopathology” subsection ended with:

“Going forward, studies must explore the longitudinal effects of early trauma on methylation as well as comparisons of multiple loci methylation patterns and interactions to determine the greatest factors contributing to health outcomes. Only then, can we start to consider the role of sex in moderating risk.”

I didn’t agree with the cause-ignoring approach of the behavior therapy mentioned in the review. Does it make sense to approach one category of symptoms:

“the biological effects of early life stress”

by treating another category of symptoms?

“can be reversed in the face of evidence-based behavioral interventions.”

But addressing symptoms instead of the sometimes-common causes that generate both biological and behavioral effects continues to be the direction.

After receiving short-term symptom relief, wouldn’t people prefer treatments of originating causes so that their various symptoms don’t keep bubbling up? Why wouldn’t research paradigms be aligned accordingly?

I was encouraged by the intergenerational and transgenerational focus of one of the reviewer’s research:

“Dr. Gonzalez’s current research focus is to understand the mechanisms by which early experiences are transmitted across generations and how preventive interventions may affect this transmission.”

This line of hypotheses requires detailed histories, and should uncover causes for many effects that researchers may otherwise shrug off as unexplainable individual differences. Its aims include the preconception through prenatal periods when both the largest and the largest number of epigenetic changes occur, and is when our susceptibility and sensitivity to our environment is greatest. There are fewer opportunities for effective “preventive interventions” in later life compared with these early periods.

Unlike lab rats, women and men can reach some degree of honesty about our early lives’ experiential causes of ongoing adverse effects. Experiential therapies that allow humans to potentially change their responses to these causes deserve more investigation than do therapies that apply external “interventions.”

https://www.sciencedirect.com/science/article/pii/S0272735817302647 “Biological alterations affecting risk of adult psychopathology following childhood trauma: A review of sex differences” (not freely available) Thanks to lead author Dr. Ashwini Tiwari for providing a copy.

Differing approaches to a life wasted on beliefs

gettingwell4 4-5 stars Advanced knowledge, Amygdala, Anterior cingulate cortex, Beliefs, Brain development, Brain hemispheres, Brainstem, Cerebrum, Cortisol, Dopamine, Epigenetics, Glutamate, Hippocampus, Hypothalamus, Limbic system, Locus coeruleus, Lower brain, Memory, Neurochemicals, Oxytocin, Primal Therapy, Serotonin, Stress, Thalamus , , , , , , , , , ,

Let’s start by observing that people structure their lives around beliefs. As time goes on, what actions would a person have taken to ward off non-confirming evidence?

One response may be that they would engage in ever-increasing efforts to develop new beliefs that justified how they spent their one precious life’s time so far.

Such was my take on beliefs embedded in https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5684598/pdf/PSYCHIATRY2017-5491812.pdf “Epigenetic and Neural Circuitry Landscape of Psychotherapeutic Interventions”:

“Animal models have shown the benefits of continued environmental enrichment (EE) on psychopathological phenotypes, which carries exciting translational value.

This paper posits that psychotherapy serves as a positive environmental input (something akin to EE).”

The author conveyed his belief that wonderful interventions were going to happen in the future. However, when scrutinized, most human studies have demonstrated NULL effects of psychotherapeutic interventions on causes. Without sound evidence that treatments affect causes, his belief seemed driven by something else.

The author cited findings of research like A problematic study of oxytocin receptor gene methylation, childhood abuse, and psychiatric symptoms as supporting external interventions to tamp down symptoms of patients’ presenting problems. Did any of the 300+ cited references concern treatments where patients instead therapeutically addressed their problems’ root causes?

For an analogous religious example, a person’s belief caused him to spend years of his life trying to convince men to act so that they could get their own planet after death, and trying to convince women to latch onto men who had this belief. A new and apparently newsworthy belief developed from his underlying causes:

“The founder and CEO of neuroscience company Kernel wants “to expand the bounds of human intelligence.” He is planning to do this with neuroprosthetics; brain augmentations that can improve mental function and treat disorders. Put simply, Kernel hopes to place a chip in your brain.

He was raised as a Mormon in Utah and it was while carrying out two years of missionary work in Ecuador that he was struck by what he describes as an “overwhelming desire to improve the lives of others.”

He suffered from chronic depression from the ages of 24 to 34, and has seen his father and stepfather face huge mental health struggles.”

https://www.theguardian.com/small-business-network/2017/dec/14/humans-20-meet-the-entrepreneur-who-wants-to-put-a-chip-in-your-brain “Humans 2.0: meet the entrepreneur who wants to put a chip in your brain”

The article stated that he had given up Mormonism. There was nothing to suggest, though, that he had therapeutically addressed any underlying causes for his misdirected thoughts, feelings, and behavior.

So he developed other beliefs instead.

What can people do to keep their lives from being wasted on beliefs? As mentioned in What was not, is not, and will never be:

“The problem is that spending our time and efforts on these ideas, beliefs, and behaviors won’t ameliorate their motivating causes. Our efforts only push us further away from our truths, with real consequences: a wasted life.”

The goal of the therapeutic approach advocated by Dr. Arthur Janov’s Primal Therapy is to remove the force of presenting problems’ motivating causes. Success in reaching this goal is realized when patients become better able to live their own lives.

Experience-induced transgenerational programming of neuronal structure and functions

gettingwell4 2-3 stars Required further work, Amygdala, Anterior cingulate cortex, Brain development, Brainstem, Cerebrum, Cortisol, Dopamine, Epigenetics, Glutamate, Hippocampus, Hypothalamus, Limbic system, Locus coeruleus, Lower brain, Memory, Neurochemicals, Oxytocin, Serotonin, Stress , , , , , , , , , , ,

The second paper of Transgenerational epigenetic inheritance week was a 2017 German/Israeli review focused on:

“The inter- and transgenerational effects of stress experience prior to and during gestation..the concept of stress-induced (re-)programming in more detail by highlighting epigenetic mechanisms and particularly those affecting the development of monoaminergic transmitter systems, which constitute the brain’s reward system.

We offer some perspectives on the development of protective and therapeutic interventions in cognitive and emotional disturbances resulting from preconception and prenatal stress.”

The reviewers noted that human studies have difficulties predicting adult responses to stress that are based on gene expression and early life experience. Clinical studies that experimentally manipulate the type, level and timing of the stressful exposure aren’t possible. Clinical studies are also predicated on the symptoms being recognized as disorders and/or diseases.

The researchers noted difficulties in human interventions and treatments. Before and during pregnancy, and perinatal periods are where stress effects are largest. But current human research hasn’t gathered sufficient findings to develop practical guidelines for early intervention programs.

I’m not persuaded by arguments that cite the difficulties of performing human research on transgenerational epigenetic inheritance. There are overwhelming numbers of people who have obvious stress symptoms: these didn’t develop in a vacuum.

Researchers:

  • Design human studies to test what’s known from transgenerational epigenetic inheritance animal studies that will include documenting the subjects’ detailed histories with sufficient biometric samples and data obtained from their lineage.
  • Induce pregnant subjects to at least temporarily avoid what’s harmful for them and/or the offspring, in favor of what’s beneficial.
  • Document the subjects’ actions with history and samples.

I acknowledge that economic incentives may not be enough to get people to participate. I’m familiar with a juvenile sickle-cell study that didn’t get enough subjects despite offering free transportation and hundreds of dollars to the caregivers per visit. The main problem seemed to be that the additional income would be reported and threaten the caregivers’ welfare benefits.

Stop whining that your jobs are difficult, researchers. Society doesn’t owe you a job. EARN IT – get yourself and the people in your organization motivated to advance science!

http://www.sciencedirect.com/science/article/pii/S014976341630731X “Experience-induced transgenerational (re-)programming of neuronal structure and functions: Impact of stress prior and during pregnancy” (not freely available)

Does living near a forest keep your amygdala healthier?

gettingwell4 2-3 stars Required further work, Amygdala, Anterior cingulate cortex, Cerebrum, Cortisol, Hippocampus, Limbic system, Neurochemicals, Stress ,

A thought-provoking post from A Paper a Day Keeps the Scientist Okay entitled “Living Near a Forest Keeps Your Amygdala Healthier” referenced a 2017 German human study which found:

“..a relationship between place of residence and brain health: those city dwellers living close to a forest were more likely to show indications of a physiologically healthy amygdala structure and were therefore presumably better able to cope with stress.”

The researchers accomplished the imperative of meeting the study’s stated objective:

“We set out to identify and characterize the geographical elements of a city that are associated with these brain structures following a suggestion by Kennedy and Adolph that studies should begin to derive recommendations for urban planning and architecture.

The results of our study may suggest that forests in and around the cities are a valuable resource that should be promoted. However future longitudinal studies are needed to investigate the causal directionality of the effect in order to disentangle whether more forest in ones habitat facilitates brain structural integrity or potentially those people with better brain structural integrity choose to live closer to forests. Moreover we need to investigate whether living close to the forest is associated with an absence of risk factors such as noise, air pollution or stress and thereby has beneficial effects or whether the forest itself constitutes a salutary factor that promotes well-being.”

https://www.nature.com/articles/s41598-017-12046-7 “In search of features that constitute an “enriched environment” in humans: Associations between geographical properties and brain structure”

A major limitation of this study’s methodology was intentional non-use of an available data source. Referring to Do we need to study the brain to understand the mind? posted earlier this week:

“Self-report is still the gold standard for assessing emotional experience and the contents of thought. Isn’t it easier just to ask?”

These researchers put the forest before the trees, and designed a study that didn’t ask subjects important questions such as why they lived where they lived. The researchers inferred sketchy fMRI-geography associations because they didn’t solicit relevant primary information via individual self-reports.

I don’t live in Berlin, and I’m not part of the selected cohort, but I otherwise generally meet this study’s subject parameters. Something in my past causes me to actively select housing that isn’t in a noisy environment. If I were asked why I lived where I lived, my answer would have included:

  • A deciding factor in why I sold my second house was traffic noise in wintertime;
  • A deciding factor in why I bought my fourth house was its location in the housing development’s center, away from street noise; and
  • A deciding factor in why I live where I now live is the house’s orientation away from both direct and reflective traffic noise sources.

Processing my hypothetical fMRI data with my self-reported historical housing choices may or may not have found:

“Geographical features in the proximal participants’ habitat are associated with brain integrity.”

Using better-quality information of self-reports, though, it’s unlikely that an association this study would have found to be significant – a chance fact that I live within one kilometer of a forest – would have been deemed significant.

Do we need to study the brain to understand the mind?

gettingwell4 4-5 stars Advanced knowledge, Amygdala, Anterior cingulate cortex, Cerebrum, Hippocampus, Limbic system, Memory

A coauthor of the studies referenced in:

offered an opinion piece in A Paper a Day Keeps the Scientist Okay entitled “Do We Need To Study The Brain To Understand The Mind?”

“The emerging consensus appears to be that implementation is important. Interestingly, the inverse question is also being asked by neurobiologists—do we need consider the mind to understand the brain?—and answered largely and increasingly in the affirmative.

Is pain different from negative emotions such as sadness and anger, or are they variants on a common theme? Pain appears to be distinct from negative emotion, but commonalities suggest ways in which they may share underlying processes such as heightened attention.

One of the biggest pitfalls is the temptation to observe brain activity and make inferences about the psychological state—for example, to infer:

  • Episodic memory retrieval from hippocampal activity,
  • Fear from amygdala activity, or
  • Visual processing from activity in the ‘visual cortex.’

These inferences ignore the scope of processes which may activate each of these areas and involve a fallacy in reasoning: “if memory then hippocampus” is not the same thing as “if hippocampus then memory.”

The fact that few brain areas, including the ‘visual cortex,’ are dedicated to one process means that self-report is still the gold standard for assessing emotional experience and the contents of thought. This is a serious challenge for those who would like, for example, to assess your brand preferences or your political affiliation from a brain scan. (And isn’t it easier just to ask?)”

Epigenetic effects of early life stress exposure

gettingwell4 5+ stars Premium, Amygdala, Anterior cingulate cortex, Brain development, Brainstem, Cerebrum, Cortisol, Dopamine, Epigenetics, Glutamate, Hippocampus, Hypothalamus, Limbic system, Locus coeruleus, Lower brain, Memory, Neurochemicals, Primal Therapy, Serotonin, Stress, Thalamus, Vasopressin , , , , , , , , ,

This 2017 Netherlands review subject was the lasting epigenetic effects of early-life stress:

“Exposure to stress during critical periods in development can have severe long-term consequences.

One of the key stress response systems mediating these long-term effects of stress is the hypothalamic-pituitary-adrenal (HPA) axis.

Early life stress (ELS) exposure has been reported to have numerous consequences on HPA-axis function in adulthood.

ELS is able to “imprint” or “program” an organism’s neuroendocrine, neural and behavioral responses to stress. Research focuses along two complementary lines:

  1. ELS during critical stages in brain maturation may disrupt specific developmental processes (by altered neurotransmitter exposure, gene transcription, or neuronal differentiation), leading to aberrant neural circuit function throughout life.
  2. ELS may induce modifications of the epigenome which lastingly affect brain function.

These epigenetic modifications are inducible, stable, and yet reversible, constituting an important emerging mechanism by which transient environmental stimuli can induce persistent changes in gene expression and ultimately behavior.”

In early life, the lower brain and limbic system brain structures are more developed and dominant, whereas the cerebrum is less developed (use the above rodent graphic as a rough guide). Stress and pain generally have a greater impact on a fetus than an infant, and a greater impact on an infant than an adult.

The reviewers cited 50+ studies from years 2000-2015 in the “Early Life Stress Effects in a “Matching” Stressful Adult Environment” section to argue for the match / mismatch theory:

“Encountering ELS prepares an organism for similar (“matching”) adversities during adulthood, while a mismatching environment results in an increased susceptibility to psychopathology, indicating that ELS can exert either beneficial or disadvantageous effects depending on the environmental context.

Initial evidence for HPA-axis hypo-reactivity is observed for early social deprivation, potentially reflecting the abnormal HPA-axis function as observed in post-traumatic stress disorder.

Experiencing additional (chronic) stress in adulthood seems to normalize these alterations in HPA-axis function, supporting the match / mismatch theory.”

Evidence for this theory was contrasted with the allostatic load theory presented in How one person’s paradigms regarding stress and epigenetics impedes relevant research.

The review mainly cited evidence from rodent studies that mismatched reactions in adulthood may be consequences of early-life events. These events:

“Imprint or program an organism’s neuroendocrine, neural and behavioral responses..leading to aberrant neural circuit function throughout life..which lastingly affect brain function.”

Taking this research to a personal level:

  • Have you had feelings that you were unsafe, although your environment was objectively safe?
  • Have you felt uneasy when people are nice to you?
  • Have you felt anxious when someone pays attention to you, even after you’ve acted to gain their attention?

Mismatched human feelings are one form of mismatched reactions. These may be consequences of early-life experiences, and indicators of personal truths.

If researchers can let go of their biases and Advance science by including emotion in research, they may find that human subjects’ feelings produce better evidence for what actually happened during the subjects’ early lives than do standard scientific methods of:

Incorporating feeling evidence may bring researchers and each individual closer to discovering the major insults that knocked their development processes out of normally robust pathways and/or induced “persistent changes in gene expression and ultimately behavior.”

https://www.frontiersin.org/articles/10.3389/fncel.2017.00087/full “Modulation of the Hypothalamic-Pituitary-Adrenal Axis by Early Life Stress Exposure”

I came across this review as a result of it being cited in http://www.sciencedirect.com/science/article/pii/S1084952117302884 “Long-term effects of early environment on the brain: Lesson from rodent models” (not freely available)

Observing pain in others had long-lasting brain effects

gettingwell4 4-5 stars Advanced knowledge, Anterior cingulate cortex, Brain hemispheres, Cerebrum, Limbic system, Memory, Neurochemicals, Oxytocin, Stress , ,

This 2016 Israeli human study used whole-head magnetoencephalography (MEG) to study pain perception in military veterans:

“Our findings demonstrate alterations in pain perception following extreme pain exposure, chart the sequence from automatic to evaluative pain processing, and emphasize the importance of considering past experiences in studying the neural response to others’ states.

Differences in brain activation to ‘pain’ and ‘no pain’ in the PCC [posterior cingulate cortex] emerged only among controls. This suggests that prior exposure to extreme pain alters the typical brain response to pain by blurring the distinction between painful and otherwise identical but nonpainful stimuli, and that this blurring of the ‘pain effect’ stems from increased responses to ‘no pain’ rather than from attenuated response to pain.”

Limitations included:

  • “The pain-exposed participants showed posttraumatic symptoms, which may also be related to the observed alterations in the brain response to pain.
  • We did not include pain threshold measurements. However, the participants’ sensitivity to experienced pain may have had an effect on the processing of observed pain.
  • The regions of interest for the examination of pain processing in the pain-exposed group were defined on the basis of the results identified in the control group.
  • We did not detect pain-related activations in additional regions typically associated with pain perception, such as the anterior insula and ACC. This may be related to differences between the MEG and fMRI neuroimaging approaches.”

The subjects self-administered oxytocin or placebo per the study’s design. However:

“We chose to focus on the placebo condition and to test group differences at baseline only, in light of the recent criticism on underpowered oxytocin administration studies, and thus all following analyses are reported for the placebo condition.”

A few questions:

  1. If observing others’ pain caused “increased responses to ‘no pain’,” wouldn’t the same effect or more be expected from experiencing one’s own pain?
  2. If there’s evidence for item 1, then why aren’t “increased responses to ‘no pain'” of affected people overtly evident in everyday life?
  3. If item 2 is often observed, then what are the neurobiological consequences for affected people’s suppression of “increased responses to ‘no pain’?”
  4. Along with the effects of item 3, what may be behavioral, emotional, and other evidence of this suppressed pain effect?
  5. What would it take for affected people to regain a normal processing of others’ “‘pain’ and ‘no pain’?”

https://www.researchgate.net/publication/299546838_Prior_exposure_to_extreme_pain_alters_neural_response_to_pain_in_others “Prior exposure to extreme pain alters neural response to pain in others” Thanks to one of the authors, Ruth Feldman, for providing the full study

The current paradigm of child abuse limits pre-childhood causal research

gettingwell4 < 0 Detracted from science, Amygdala, Anterior cingulate cortex, Brain development, Brainstem, Cerebrum, Cortisol, Epigenetics, Hippocampus, Hypothalamus, Limbic system, Locus coeruleus, Lower brain, Neurochemicals, Oxytocin, Serotonin, Stress, Telomeres, Testosterone, Thalamus, Vasopressin , , , , ,

As an adult, what would be your primary concern if you suspected that your early life had something to do with current problems? Would you be interested in effective treatments for causes of your symptoms?

Such information wasn’t available in this 2016 Miami review of the effects of child abuse. The review laid out the current paradigm mentioned in Grokking an Adverse Childhood Experiences (ACE) score, one that limits research into pre-childhood causes for later-life symptoms.

The review’s goal was to describe:

“How numerous clinical and basic studies have contributed to establish the now widely accepted idea that adverse early life experiences can elicit profound effects on the development and function of the nervous system.”

The hidden assumptions of almost all of the cited references were that these distant causes could no longer be addressed. Aren’t such assumptions testable today?

As an example, the Discussion section posed the top nine “most pressing unanswered questions related to the neurobiological effects of early life trauma.” In line with the current paradigm, the reviewer assigned “Are the biological consequences of ELS [early life stress] reversible?” into the sixth position.

If the current paradigm encouraged research into treatment of causes, there would probably already be plenty of evidence to demonstrate that directly reducing the source of damage would also reverse damaging effects. There would have been enough studies done so that the generalized question of reversibility wouldn’t be asked.

Aren’t people interested in treatments of originating causes so that their various symptoms don’t keep bubbling up? Why wouldn’t research paradigms be aligned accordingly?

The review also demonstrated how the current paradigm of child abuse misrepresented items like telomere length and oxytocin. Researchers on the bandwagon tend to forget about the principle Einstein expressed as:

“No amount of experimentation can ever prove me right; a single experiment can prove me wrong.”

That single experiment for telomere length arrived in 2016 with Using an epigenetic clock to distinguish cellular aging from senescence. The review’s seven citations for telomere length that all had findings “associated with” or “linked to” child abuse should now be viewed in a different light.

The same light shone on oxytocin with Testing the null hypothesis of oxytocin’s effects in humans and Oxytocin research null findings come out of the file drawer. See their references, and decide for yourself whether or not:

“Claimed research findings may often be simply accurate measures of the prevailing bias.”

http://www.cell.com/neuron/fulltext/S0896-6273%2816%2900020-9 “Paradise Lost: The Neurobiological and Clinical Consequences of Child Abuse and Neglect”

This post has somehow become a target for spammers, and I’ve disabled comments. Readers can comment on other posts and indicate that they want their comment to apply here, and I’ll re-enable comments.

A review that inadvertently showed how memory paradigms prevented relevant research

gettingwell4 < 0 Detracted from science, Amygdala, Anterior cingulate cortex, Cerebrum, Epigenetics, Glutamate, Hippocampus, Limbic system, Memory, Neurochemicals, Stress , , , , ,

This 2016 Swiss review of enduring memories demonstrated what happens when scientists’ reputations and paychecks interfered with them recognizing new research and evidence in their area but outside their paradigm: “A framework containing the basic assumptions, ways of thinking, and methodology that are commonly accepted by members of a scientific community.”

A. Most of the cited references were from decades ago that established these paradigms of enduring memories. Fine, but the research these paradigms excluded was also significant.

B. All of the newer references were continuations of established paradigms. For example, a 2014 study led by one of the reviewers found:

“Successful reconsolidation-updating paradigms for recent memories fail to attenuate remote (i.e., month-old) ones.

Recalling remote memories fails to induce histone acetylation-mediated plasticity.”

The researchers elected to pursue a workaround of the memory reconsolidation paradigm when the need for a new paradigm of enduring memories directly confronted them!

C. None of the reviewers’ calls for further investigations challenged existing paradigms. For example, when the reviewers suggested research into epigenetic regulation of enduring memories, they somehow found it best to return to 1984, a time when dedicated epigenetics research had barely begun:

“Whether memories might indeed be ‘coded in particular stretches of chromosomal DNA’ as originally proposed by Crick [in 1984] and if so what the enzymatic machinery behind such changes might be remain unclear. In this regard, cell population-specific studies are highly warranted.”

Two examples of relevant research the review failed to consider:

1. A study that provided evidence for basic principles of Primal Therapy went outside existing paradigms to research state-dependent memories:

“If a traumatic event occurs when these extra-synaptic GABA receptors are activated, the memory of this event cannot be accessed unless these receptors are activated once again.

It’s an entirely different system even at the genetic and molecular level than the one that encodes normal memories.”

What impressed me about that study was the obvious nature of its straightforward experimental methods. Why hadn’t other researchers used the same methods decades ago? Doing so could have resulted in dozens of informative follow-on study variations by now, which is my point in Item A. above.

2. A relevant but ignored 2015 French study What can cause memories that are accessible only when returning to the original brain state? which supported state-dependent memories:

“Posttraining/postreactivation treatments induce an internal state, which becomes encoded with the memory, and should be present at the time of testing to ensure a successful retrieval.”

The review also showed the extent to which historical memory paradigms depend on the subjects’ emotional memories. When it comes to human studies, though, designs almost always avoid studying emotional memories.

It’s clearly past time to Advance science by including emotion in research.

http://www.hindawi.com/journals/np/2016/3425908/ “Structural, Synaptic, and Epigenetic Dynamics of Enduring Memories”

What’s the underlying question for every brain study to answer?

gettingwell4 2-3 stars Required further work, Amygdala, Anterior cingulate cortex, Beliefs, Cerebrum, Cortisol, Dopamine, Epigenetics, Glutamate, Hippocampus, Hypothalamus, Limbic system, Memory, Neurochemicals, Primal Therapy, Serotonin, Stress, Testosterone, Thalamus , , , , , ,

Is the underlying question for every brain study to answer:

  • How do our brains internally represent the external world?

Is it:

  • How did we learn what we know?
  • How do we forget or disregard what we’ve learned?
  • What keeps us from acquiring and learning newer or better information?

How about:

  • What affects how we pay attention to our environments?
  • How do our various biochemical states affect our perceptions, learning, experiences, and behavior?
  • How do these factors in turn affect our biology?

Or maybe:

  • Why do we do what we do?
  • How is our behavior affected by our experiences?
  • How did we become attracted and motivated toward what we like?
  • How do we develop expectations?
  • Why do we avoid certain situations?

Not to lose sight of:

  • How do the contexts affect all of the above?
  • What happens over time to affect all of the above?

This 2015 UCLA paper reviewed the above questions from the perspective of Pavlovian conditioning:

“The common definition of Pavlovian conditioning, that via repeated pairings of a neutral stimulus with a stimulus that elicits a reflex the neutral stimulus acquires the ability to elicit that the reflex, is neither accurate nor reflective of the richness of Pavlovian conditioning. Rather, Pavlovian conditioning is the way we learn about dependent relationships between stimuli.

Pavlovian conditioning is one of the few areas in biology in which there is direct experimental evidence of biological fitness.”

The most important question unanswered by the review was:

  • How can its information be used to help humans?

How can Pavlovian conditioning answer: What can a human do about the thoughts, feelings, behavior, epigenetic effects – the person – the phenotype – that they’ve been shaped into?

One example of the unanswered question: the review pointed out in a section about fear extinction that this process doesn’t involve unlearning. Fear extinction instead inhibits the symptoms of fear response. The fear memory is still intact, awaiting some other context to be reactivated and expressed.

How can this information be used to help humans?

  • Is inhibiting the symptoms and leaving the fear memory in place costless with humans?
  • Or does this practice have both potential and realized adverse effects?
  • Where’s the human research on methods that may directly address a painful emotional memory?

One relevant hypothesis of Dr. Arthur Janov’s Primal Therapy is that a person continues to be their conditioned self until they address the sources of their pain. A corollary is that efforts to relieve symptoms seldom address causes.

How could it be otherwise? A problem isn’t cured by ameliorating its effects.

http://cshperspectives.cshlp.org/content/8/1/a021717.full “The Origins and Organization of Vertebrate Pavlovian Conditioning”

Empathy, value, pain, control: Psychological functions of the human striatum

gettingwell4 5+ stars Premium, Anterior cingulate cortex, Brain hemispheres, Cerebrum, Dopamine, Limbic system, Memory, Neurochemicals, Thalamus , ,

This 2016 US human study found:

“A link between existing data on the anatomical and physiological characteristics of striatal regions and psychological functions.

Because we did not limit our metaanalysis to studies that specifically targeted striatal function, our results extend previous knowledge of the involvement of the striatum in reward-related decision-making tasks, and provide a detailed functional map of regional specialization for diverse psychological functions, some of which are sometimes thought of as being the exclusive domain of the PFC [prefrontal cortex].”

The analysis led to dividing the striatum into five segments:

Ventral striatum (VS):

  • Stimulus Value
  • Terms such as “reward,” “losses,” and “craving”
  • The most representative study reported that monetary and social rewards activate overlapping regions within the VS.
  • Together with the above finding of a reliable coactivation with OFC [orbitofrontal cortex] and ventromedial PFC, this finding suggests a broad involvement of this area in representing stimulus value and related stimulus-driven motivational states.

Anterior caudate (Ca) Nucleus:

  • Incentive Behavior
  • Terms such as “grasping,” “reaching,” and “reinforcement”
  • The most representative study reported a stronger blood-oxygen level-dependent (BOLD) response in this region during trials in which participants had a chance of winning or losing money in a card guessing game, in comparison to trials where participants merely received feedback about the accuracy of their guess.
  • This result suggests a role in evaluating the value of different actions, contrasting with the above role of the VS in evaluating the value of stimuli.

Posterior putamen (Pp):

  • Sensorimotor Processes
  • Terms such as “foot,” “noxious,” and “taste”
  • The most representative study reported activation of this region in response to painful stimulation at the back of the left hand and foot of participants. Anatomically, the most reliable and specific coactivation is with sensorimotor cortices, and the posterior and midinsula and operculum (secondary somatosensory cortex SII) in particular, some parts of which are specifically associated with pain.
  • Together, these findings suggest a broad involvement of this area in sensorimotor functions, including aspects of their affective qualities.

Anterior putamen (Pa):

  • Social- and Language-Related Functions
  • Terms such as “read,” “vocal,” and “empathic”
  • The most representative study partially supports a role of this area in social- and language-related functions; it reported a stronger activation of the Pa in experienced singers, but not when novices were singing.
  • It is coactivated with frontal areas anterior to the ones coactivated with the Pp, demonstrating topography in frontostriatal associations. These anterior regions have been implicated in language processes.

Posterior caudate (Cp) Nucleus:

  • Executive Functions
  • Terms such as “causality,” “rehearsal,” and “arithmetic”
  • The representative study reported this region to be part of a network that included dorsolateral PFC and ACC, which supported inhibitory control and task set-shifting.
  • These results suggest a broad, and previously underappreciated, role for the Cp in cognitive control.

The authors presented comparisons of the above striatal segments with other analyses of striatal zones.

One of the coauthors was the lead researcher of the 2015 Advance science by including emotion in research. The current study similarly used a coactivation view rather than a connectivity paradigm of:

“Inferring striatal function indirectly via psychological functions of connected cortical regions.”

Another of the coauthors was a developer of the system used by the current study and by The function of the dorsal ACC is to monitor pain in survival contexts, and he provided feedback to those authors regarding proper use of the system.

The researchers’ “unbiased, data-driven approach” had to work around the cortical biases evident in many of the 5,809 human imaging studies analyzed. The authors referred to the biases in statements such as:

“The majority of studies investigating these psychological functions report activity preferentially in cortical areas, except for studies investigating reward-related and motor functions.”

The methods and results of research with cortical biases influenced the study’s use of:

“Word frequencies of psychological terms in the full text of studies, rather than a detailed analysis of psychological tasks and statistical contrasts.”

http://www.pnas.org/content/113/7/1907.full “Regional specialization within the human striatum for diverse psychological functions”