Limbic system

Problematic research that ignored the hippocampus as the seat of emotional memories

gettingwell4 < 0 Detracted from science, Cerebrum, Hippocampus, Limbic system, Memory

If this 2015 human study from the San Diego Veterans Administration developed findings of any note, I didn’t see them.

Like other studies, this study ignored the hippocampus’ position as the seat of emotional memories. The experiments were designed to not contain any emotional content.

The researchers mainly wanted to fight a 60-year old battle on whether or not the hippocampus contributed to spatial processing. They ignored all the research on place cells, such as:

to name three of the hundreds of place cell studies available.

By ignoring these and other studies, the researchers declared:

“We have not found evidence that this is the case.”

The lead researcher continued with speculations that couldn’t be verified with the current experiments’ data:

“We think they can do these spatial tasks because these tasks can be managed within short-term memory functions, supported by the frontal lobe of the neocortex.

The spatial tasks that we can do with our neocortex using short-term memory must be performed by the hippocampus in rats.”

Basically, the rest of the scientific world must supply irrefutable evidence (which will be ignored) but the reader can just take the lead researcher’s words as fact for what’s going on inside human and rodent brains, although:

  • No fMRI scans were performed during the experiments,
  • No hard measurements were taken.

The findings were based on observations of six subjects:

  • With hippocampal lesions of unspecified duration,
  • Drawing pictures, and
  • Narrating what they imagined about a playground.

I wonder what the reviewers saw in this study that factually advanced science. Did the statement:

“These results support the traditional view that the human hippocampus is primarily important for memory.”

convey something new? Make a contribution to science?

Studies like this one not only detract from science. They are also a waste of resources that supposedly the Veterans Administration have in short supply.

The design and data of such studies are not able to reach levels where they can provide evidence of causes and effects of anything within their scope. That’s a good indication of some other agenda in play.

http://www.pnas.org/content/112/15/4767.full “Memory, scene construction, and the human hippocampus”

The amygdala part of the limbic system doesn’t process beliefs

gettingwell4 0-1 star Wasted resources, Amygdala, Beliefs, Cerebrum, Limbic system

Does your desk light switch on or off when other people in the office switch their desk lights on or off? Something in the wiring would probably be wrong if it did.

And wouldn’t you expect that other desk lights would still operate normally if your desk light’s bulb burned out, although everyone may be plugged into the same electrical circuit?

It surprised the researchers of this 2015 CalTech/MIT study when:

“Two patients with bilateral amygdala lesions performed a belief reasoning test.

Both patients showed typical test performance and cortical activity when compared with nearly 500 healthy controls.”

The study’s overall frame of reference was expressed as:

“Humans use a so-called “theory-of-mind” to reason about the beliefs of others. Neuroimaging studies of belief reasoning suggest it activates a specific cortical network. The amygdala is interconnected with this network and plays a fundamental role in social behavior.”

The experimental test:

“Was designed to optimize functional contrast in those brain regions thought to be involved in attempts, be they successful or unsuccessful, to evaluate the veracity of another person’s belief about the world.”

A “belief reasoning test..to reason about the beliefs of others” is a cerebral exercise. The amygdala, in contrast, is an emotional center of a person’s limbic system.

The logic by which the study may be viewed is:

  1. The “belief reasoning test” had no emotional content to activate the subjects’ amygdalae.
  2. fMRI scans confirmed that limbic system areas in the 2 lesioned subjects weren’t activated during the test.
  3. Apply the logic of Occam’s razor, and we arrive at the findings of “typical test performance and cortical activity.”

Task performance and beliefs about task responses are solely cerebral exercises had a similar methodology and result in that those subjects’ limbic systems were monitored during fMRI scans and subsequent reporting, but the subjects’ limbic system areas weren’t activated during any of the experiments.

The researchers stated the results:

“Suggest a reevaluation of the role of the amygdala and its cortical interactions in human social cognition.”

But per the beginning analogy – if your desk light’s bulb burned out, would you be surprised that it didn’t affect the normal operations of desk lights in other offices, although they all may be plugged into the same circuit?

This study informed us that the amygdala isn’t slaved to the cerebrum. It’s hard to change the current research mindset/social meme of cerebral dominance, though, so maybe this information will be overlooked.

http://www.pnas.org/content/112/15/4827.full “Amygdala lesions do not compromise the cortical network for false-belief reasoning”

Can you give emotionally informed yet reasoned responses to moral questions within 3 seconds?

gettingwell4 0-1 star Wasted resources, Beliefs, Cerebrum, Limbic system, Memory

Could you give a 3-second informed decision that reflected your true feelings about this statement?

“Inflicting emotional harm is just as bad as inflicting physical harm.”

Could you then express your confidence about your answer on a 1-7 scale within 1 second? How about your 3-second response to this statement:

“Developing a child’s character is central to raising it good.”

The researchers of this 2015 Swedish study asserted that it:

“Demonstrates that moral choices are no different from their preferential and perceptual counterparts; they are highly constrained and coupled to the immediate environment through sensory interaction.”

The subjects’ moral choices about statements such as:

“One should never intentionally harm another person.”

weren’t weighted any differently than their “top of the head” answers to questions such as:

“Is Denmark larger than Sweden?”

There was a time limit of 3 seconds for the subjects to answer 63 “moral” and 35 “factual” questions. The subjects were asked to express their confidence in the answer during an additional 1-second time frame. Answers after these time limits were discarded.

In the supplementary material, the researchers:

“Justified our design. When no time-out condition was included, 33% of participants realized that their eye movements were influencing the timing of the trial.”

So the 3-second time frame was imposed to keep the subjects from gaming the experiment. The experiment’s time limit of 3 seconds didn’t have anything to do with properly modeling moral decision-making.

The time period wasn’t the only questionable area. The researchers focused on eye gaze as the important homogenous factor influencing the subjects as they made their “moral” choices.

However, one person’s eye gaze is not necessarily the same as the next person’s, as demonstrated by studies such as:

An individual’s attention and perception that are incorporated into their eye gaze are behaviors that may have many differing historical components. For example, one subject may have kept their gaze on the:

“Value animals equally.”

answer to the:

“Animal welfare should not be valued equally with human welfare.”

question because their initial reaction involved their cuddly pet. Another subject may have kept their gaze on the same answer because their initial reaction involved a stray dog that attacked them.

Did the study shed light on its initial statement?

“Moral cognition arises from the interplay between emotion and reason.”

I didn’t see that the study’s design allowed its subjects to produce emotionally informed yet reasoned responses to the 98-question battery.

http://www.pnas.org/content/112/13/4170.full “Biasing moral decisions by exploiting the dynamics of eye gaze”

Are hippocampal place cells controlled by theta brain waves from grid cells?

gettingwell4 2-3 stars Required further work, Hippocampus, Limbic system, Memory

This 2015 Canadian rodent study tried to establish that grid cells in the medial entorhinal cortex generated brain waves in the theta frequency range that controlled place cells in the hippocampus part of the limbic system.

The researchers stated:

“Our results deviate from the prediction.”

but a commentary Do the spatial frequencies of grid cells mold the firing fields of place cells? said the researchers:

“Obtained fascinating results, largely supporting the model.”

What’s fascinating to me is the volume of studies on the hippocampus that ignore its position as the seat of emotional memories. Human experiments involving the hippocampus are usually designed to not contain any emotional content.

Two studies showed functions of hippocampal place cells:

A summary study of 118 other studies What do grid cells contribute to place cell firing? provided additional information on grid cells and hippocampal place cells, head direction cells, boundary cells, and cells that encode object locations.

The summary study related to the current study by stating that the research through early 2014 arguably found:

“Grid and place cell firing patterns are not successive stages of a processing hierarchy, but complementary and interacting representations that work in combination.”

http://www.pnas.org/content/112/13/4116.full “Place field expansion after focal MEC inactivations is consistent with loss of Fourier components and path integrator gain reduction”

A common dietary supplement that has rapid and lasting antidepressant effects

gettingwell4 4-5 stars Advanced knowledge, Cerebrum, Epigenetics, Glutamate, Hippocampus, Limbic system, Neurochemicals, Stress , , ,

This 2012 Italian rodent study found that a common dietary supplement had rapid and lasting antidepressant effects:

“Remarkably, L-acetylcarnitine displayed a clear-cut antidepressant effect already after 3 and 7 d[ays] of daily dosing. No tolerance was developed to the action of L-acetylcarnitine. The drug was even more effective after 21 d[ays], and the effect persisted for at least 2 w[ee]k[s] after drug withdrawal.”

The researchers studied stressed mice and rats to determine that:

  1. An effect of the stress was to epigenetically change the hippocampus to produce less of an important molecule – type 2 metabotropic glutamate (mGlu2).
  2. A reduction of the mGlu2 molecule decreased the hippocampus’ regulation of the glutamate neurotransmitter.
  3. Under-regulation of glutamate, in turn, caused symptoms of depression.

L-acetylcarnitine reversed the immediate causes of stress-induced symptoms by acetylating histone proteins. These control the transcription of the brain-derived neurotrophic factor (BDNF) and mGlu2 receptors in the hippocampus and prefrontal cortex.

LAC putative action

A commentary on this research, Next generation antidepressants, had the above graphic that showed possible mechanisms for the effects of L-acetylcarnitine. Epigenetic histone modifications seem to be more easily reversible than epigenetic DNA methylation.

“Currently, depression is diagnosed only by its symptoms,” Nasca says. “But these results put us on track to discover molecular signatures in humans that may have the potential to serve as markers for certain types of depression.”

It’s tempting to extrapolate this study to humans and test whether depression symptoms could be effectively treated with some multiple of a normal acetyl-L-carnitine dietary supplement dose of 500 mg at $.25 a day. This dietary supplement is better for depression symptoms than placebo analyzed randomized control trials that tested and demonstrated its efficacy.

To cure stress-induced illnesses in humans, though, ultimate causes of stress should be removed or otherwise addressed.

http://www.pnas.org/content/110/12/4804.full “L-acetylcarnitine causes rapid antidepressant effects through the epigenetic induction of mGlu2 receptors”

The hypothalamus’ role in how calorie restriction delays aging

gettingwell4 4-5 stars Advanced knowledge, Hypothalamus, Limbic system, Neurochemicals

This 2015 Portuguese rodent study showed the underlying mechanism to explain why restricting calories delays aging.

A calorie reduction of 20 to 40% increased production of a normally occurring molecule (neuropeptide Y) in the hypothalamus part of the limbic system. The increased amounts of the molecule stimulated autophagy (the breakdown and recycling of cellular components) in hypothalamic neurons.

“Because both hypothalamic autophagy and neuropeptide Y levels decrease with age..modulation of hypothalamic neuropeptide Y levels may be considered a potential strategy to produce protective effects against hypothalamic impairments associated with age and to delay aging.”

http://www.pnas.org/content/112/13/E1642.full “Neuropeptide Y stimulates autophagy in hypothalamic neurons”

A study of visual perception that didn’t inform us about human conscious awareness

gettingwell4 0-1 star Wasted resources, Cerebrum, Limbic system, Lower brain ,

This 2015 Vanderbilt study with a Princeton reviewer stated that they found “compelling evidence” related to:

“How the brain begets conscious awareness.

Identifying the fingerprints of consciousness in humans would be a significant advancement for basic and medical research, let alone its philosophical implications on the underpinnings of the human experience.”

Let’s begin with the “conscious” part of the study’s conscious awareness goal. A summary article of 105 studies entitled Evolution of consciousness: Phylogeny, ontogeny, and emergence from general anesthesia that I curated found:

“The core of human consciousness appears to be associated primarily with phylogenetically ancient structures mediating arousal and activated by primitive emotions.”

The current study ignored the evolutionary bases of human consciousness and didn’t include any limbic system and lower brain areas. The researchers’ biases were further indicated by the statement from their press release:

“Focal theories contend there are specific areas of the brain that are critical for generating consciousness, while global theories argue consciousness arises from large-scale brain changes in activity.”

The researchers were in the “global” camp of this unnecessary divide.

Let’s next examine the “awareness” part of the study’s conscious awareness goal. The subjects were 24 students in a visual perception experiment that used fMRI. The visual events that were perceived went into the “aware” bucket and the others into the “unaware” bucket.

The study’s subject selection criteria and experiment seemed a little odd for developing “compelling evidence” related to “how the brain begets conscious awareness.” By equating visual perception with awareness, the researchers excluded the contributions of other senses and methods of awareness.

Would it follow from the study’s methodology that blind people can’t be consciously aware?

The supplementary material showed that 7 of the 24 subjects’ results for one experimental condition, and 12 – half – of the subjects’ results for another condition were excluded because they apparently had problems reporting confidence in their visual perception. I wonder why the reviewer agreed that it was appropriate to discard half of the subjects’ experimental results?

Whatever else it was that the study found, the researchers didn’t reach their goal of developing “compelling evidence” related to “how the brain begets conscious awareness.”

http://www.pnas.org/content/112/12/3799.full “Breakdown of the brain’s functional network modularity with awareness”

A study on online cooperation with limited findings

gettingwell4 0-1 star Wasted resources, Cerebrum, Limbic system, Lower brain ,

This 2015 Cambridge/Oxford study found:

“Global reputational knowledge is crucial to sustaining a high level of cooperation and welfare.”

Basically, the subjects learned how to “game” a cooperative online game, and the researchers drew up their findings.

To me, the study demonstrated part of the findings of the Reciprocity behaviors differ as to whether we seek cerebral vs. limbic system rewards study, the part where the cerebrum was active in:

“Reputation-based reciprocity, in which they help others with good reputations to gain good reputations themselves.”

The current study ignored how people’s limbic system and lower brain areas may have motivated them to cooperate.

I didn’t see how excluding people’s emotional involvement when cooperating with others improved the potential reach of this study’s findings. Doesn’t a person’s willingness to cooperate in person and in online activities usually also include their emotional motivations?

The findings can’t be applied generally to cooperative motivations and behaviors that the researchers intentionally left out of the study. The study’s findings applied just to the artificial environment of their experiment, and didn’t provide evidence for how:

“Cooperative behavior is fundamental for a society to thrive.”

http://www.pnas.org/content/112/12/3647.full “The effects of reputational and social knowledge on cooperation”

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Epigenetic DNA methylation and demethylation with the developing fetus

gettingwell4 5+ stars Premium, Brain development, Cortisol, Epigenetics, Hypothalamus, Limbic system, Neurochemicals, Oxytocin, Serotonin , ,

This extremely dense and informative 2014 UK summary study provided details about genomic imprinting:

“An unusual epigenetic process in that it is heritable and results in autosomal gene expression according to parent of origin.”

Several notes of interest:

  • Figure 3 had a fascinating sketch of how the fetus caused the mother’s hypothalamus to:

    “Determine forward maternal planning by directing/orchestrating maternal physiology and postnatal maternalism to synchronize with development of the fetus.”

  • Figure 4 followed up with a flowchart of how – with a female fetus – coexistence of three matrilineal generations in the pregnant female (her, the fetus, and the grandmother’s influence on the developing fetus’ ovarian oocytes) enabled intergenerational forward planning.
  • The study briefly noted significance of genomic imprinting on male sexual behavior, where, if processes didn’t proceed normally at this early stage of a male fetus’ development, could result in suboptimal adult behavior that didn’t change with experience.

F4.large

I’ll quote a few other unrelated passages that caught my eye.

“Reproductive success of mammals also places a considerable burden on matrilineal time and energy, with some 95% of mammalian female adult life committed to pregnancy, lactation, and maternal care.

Offspring that receive optimal nourishment and improved maternal care will be predisposed to develop a hypothalamus that is both genetically and epigenetically predisposed to this same type of good mothering.

The fetus controls its own destiny in times of acute starvation, especially in the last trimester of pregnancy, by short-term sacrifice of its placenta to preserve resources critical for brain development.”

http://www.pnas.org/content/112/22/6834.full “Genomic imprinting, action, and interaction of maternal and fetal genomes”

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Epigenetic DNA methylation of the oxytocin receptor gene affected the perception of anger and fear

gettingwell4 2-3 stars Required further work, Amygdala, Anterior cingulate cortex, Brain development, Brain hemispheres, Cerebrum, Epigenetics, Hippocampus, Limbic system, Neurochemicals, Oxytocin, Thalamus ,

This 2015 Virginia human study:

“Reveals how epigenetic variability in the endogenous oxytocin system impacts brain systems supporting social cognition and is an important step to better characterize relationships between genes, brain, and behavior.”

The researchers did a lot of things right:

  • They studied a priori selected brain areas, followed by whole brain analyses;
  • Their subjects were carefully selected

    “Because methylation levels have been shown to differ as a function of race, we restricted our sample to Caucasians of European descent”

    but they didn’t restrict subjects to the same gender;

  • They acknowledged as a limitation:

    “A lack of behavioral evidence to reveal how these epigenetic and neural markers impact the overt social phenotype.”

One thing on which I disagree with the researchers is their assessment of what needs to be done next. Their news release stated:

“When imagining the future possibilities and implications this DNA methylation and oxytocin receptor research may have, the investigators think a blood test could be developed in order to predict how an individual may behave in social situations.”

Nice idea, but the next step should be to complete the research. The next step is to develop evidence for how the oxytocin receptor gene became methylated.

The subjects had a wide range of DNA methylation at the studied gene site – from 33% to 72% methylated!

Why?

At the same gene site:

“There was a significant effect of sex such that females have a higher level of methylation than males.”

Why?

Given these significant effects, why was there no research into likely causes?

Aren’t early periods in people’s lives the most likely times when the “Epigenetic modification of the oxytocin receptor gene” that “influences the perception of anger and fear in the human brain” takes place?

Wouldn’t findings from research on the subjects’ histories potentially help other people?

http://www.pnas.org/content/112/11/3308.full “Epigenetic modification of the oxytocin receptor gene influences the perception of anger and fear in the human brain”

If you had a disease, would you agree to treatment where you became a lab rat?

gettingwell4 2-3 stars Required further work, Amygdala, Limbic system, Thalamus ,

This 2015 Czech research studied individual neurons in an area of the limbic system of Parkinson’s disease patients. The findings corroborated several findings of previous research, such as:

“We confirm the importance of the subthalamic nucleus as a hub within the limbic circuitry involved in both emotional valence and arousal processing as in two functionally and spatially segregated systems.”

This statement summed up the study for me:

“Several factors could affect our results and reduce the inferences that can be drawn with regards to the physiology of emotional processing and the role of the subthalamic nucleus in the limbic circuits.

One such factor is that the study was conducted with Parkinson’s disease patients, who are known to have a widespread central nervous system pathology and to experience problems in emotional processing.”

The current study referenced The amygdala is where we integrate our perception of human facial emotion study, which similarly used the opportunity of patients with electrodes implanted for deep-brain stimulation to study individual neurons in the amygdala. However, a design difference was that the amygdala study had healthy control subjects in addition to patients, which led to fewer potential limitations on their findings.

Also referenced was a summary study entitled Exploring emotions using invasive methods: review of 60 years of human intracranial electrophysiology. Despite excluding studies of decision making, reward processing, learning, mood disorders, and pain experiences, it didn’t demonstrate that 60 years of experiments using implanted electrodes in the brains of people with epilepsy had substantially advanced science, other than confirming what fMRI and animal research had shown.

I’m not sure how I would feel if I had a disease where the physicians treated my symptoms in such a way that I became a lab rat for research that wasn’t groundbreaking. Do people with epilepsy and Parkinson’s disease have treatments available that factually resolve the underlying causes?

http://www.pnas.org/content/112/10/3116.full “Distinct populations of neurons respond to emotional valence and arousal in the human subthalamic nucleus”

Neural plasticity trumps genetics in the hippocampus part of the limbic system

gettingwell4 2-3 stars Required further work, Brain development, Epigenetics, Hippocampus, Limbic system, Memory , ,

This 2015 rodent study used a genetic strain of mice that was bred to not express a gene that enabled long-term memory in the hippocampus. The mice were not memory-impaired, however, due to their brains’ neural plasticity.

The researchers found:

“Deletion of genes in organisms does not always give rise to phenotypes because of the existence of compensation.

The current work provides an example of how a complex brain system may adjust to the effects of gene deletion to recover function.”

The Early human brain development can be greatly modified by environmental factors study showed even greater plasticity in another part of the human brain where the people faced much larger obstacles than gene deletion.

I view this finding as a cautionary tale to reference any time a study comes out stating that A and B genes are found to cause X and Y symptoms or behavior. Researchers don’t have enough evidence in 2015 to unequivocally describe what rodent brains are capable of, much less human brains.

The researchers implied how they kept faith in their work with the phrase:

“The compensatory mechanism is imperfect and does not fully restore cGKII-dependent function.”

Is perfection the standard to which their research is also held?

http://www.pnas.org/content/112/10/3122.full “Network compensation of cyclic GMP-dependent protein kinase II knockout in the hippocampus by Ca2+-permeable AMPA receptors”

Why do we cut short our decision-making process?

gettingwell4 5+ stars Premium, Beliefs, Cerebrum, Dopamine, Limbic system, Memory, Neurochemicals, Serotonin , , ,

This 2014 Zurich study found that people adapt their goal-directed decision-making processes in certain ways.

First, the researchers found that the subjects usually acted as though the computational cost of evaluating all outcomes became too high once the process expanded to three or more levels. Their approach to a goal involved developing subgoals. For example, for a three-level goal:

“Level 3 was most frequently decomposed into a tree of depth 2 followed by a depth-1 tree.”

A level 3 tree had 24 potential outcomes (24 outcomes = 3*2x2x2) whereas a level 2 tree followed by a level 1 tree had 10 potential outcomes (10 outcomes = 2*2×2 + 1*2).

Second, the subjects memorized and reused subgoals after their initial formation. The researchers found that this practice didn’t produce results significantly different than the optimal solutions, but that could have been due to the study’s particular design. The design also ensured that the subjects’ use of subgoals wasn’t influenced by rewards.

Further:

“It is known that nonhuman primate choices, for instance, depend substantially on their own past choices, above and beyond the rewards associated with the decisions. Similar arguments have been made for human choices in a variety of tasks and settings and have been argued to be under dopaminergic and serotonergic control.”

Third, ALL 37 subjects were unwilling to evaluate decisions that had initial large losses, even if they could see that the path to reach the optimal solution went through this loss outcome! The researchers termed this behavior “pruning” and stated:

“Pruning is a Pavlovian and reflexive response to aversive outcomes.”

The lead author relied on a previous study he coauthored to elaborate on the third finding. One statement in the previous study was:

“This theory predicts excessive pruning to occur in subjects at risk for depression, and reduced pruning to occur during a depressive episode.”

The current study’s subjects were screened out for depressive conditions, though. They were somewhat conditioned by the study design, but not to the extent where their behavior could be characterized as Pavlovian responses.

Fourth, the subjects’ use of larger subgoals wasn’t correlated to their verbal IQ.

So, what can we make of this research?

  1. Are shortcuts to our decision processes strictly a cerebral exercise per the first and second findings?
  2. Do we recycle our decision shortcuts like our primate relatives, uninfluenced by current rewards?
  3. Or is it rewarding to just not fully evaluate all of our alternatives?
  4. Do all of us always back away from decisions involving an initial painful loss, even when we may see the possibility of gaining a better outcome by persevering through the loss?
  5. Is it true that we excessively cut decision processes too short – such that many of our decisions are suboptimal – when we’re on our way to becoming depressed?
  6. Are we overwhelmed when depressed such that we don’t summon up the effort to cut short or otherwise evaluate decisional input?

Let me know your point of view.

http://www.pnas.org/content/112/10/3098.full “Interplay of approximate planning strategies”

Losing track of what are symptoms and what are causes with serotonin and stress

gettingwell4 0-1 star Wasted resources, Limbic system, Neurochemicals, Serotonin, Stress, Thalamus ,

I’m starting to appreciate just how far down the rabbit hole researchers can go when they focus on symptoms and ignore causes.

This 2014 Duke study found that low-serotonin mice were more susceptible to stress than normal mice.

Okay so far, except that the study used transgenic mice that only had 20-40% of normal serotonin.

Humans most often develop low-serotonin symptoms for causes other than genetics, such as a second-order result of being subjected to childhood maltreatment and stress.

Use of the low-serotonin-due-to-genetics mice may have misdirected the researchers to lose focus that their ultimate task was to find ways that their research can help humans. If helping humans was the researchers’ focus, it may have occurred to them to show how stress caused “something” that caused low serotonin.

A second finding was that following exposure to stress, the low-serotonin mice didn’t respond to a standard antidepressant, fluoxetine. SSRI medications usually act to increase serotonin transmission, i.e. treat the symptom of low serotonin.

Stress was again not viewed as a cause of “something” that caused low serotonin. Stress was viewed as the reason that the medication didn’t work.

If helping humans was the researchers’ focus, it may have occurred to them that humans may not need medication to treat the low-serotonin symptom if the “something” that stress caused that keeps the low-serotonin symptom in place was removed.

A third finding was that inhibiting the lateral habenula area (proximal to the thalamus) with a drug relieved some depression-like behavior of the low-serotonin mice.

Okay, but one of the researchers went on to say:

“The next step is to figure out how we can turn off this brain region in a relatively non-invasive way that would have better therapeutic potential.”

Would everything would be fine if the low-serotonin mice just stopped displaying symptoms such as the depression-like behavior? Why no focus on causes, no forward thinking that maybe humans wouldn’t want part of their limbic system that performed many other functions to “turn off” just to suppress a symptom?

The researchers apparently didn’t realize their situation viz-à-viz the rabbit hole, as they circled back to the initial finding to develop a fourth finding – a possible reason that low-serotonin mice were more susceptible to stress was because a signaling molecule, β-catenin, wasn’t produced in a pathway that may be involved in resilience.

The news coverage added one more researcher quote:

“If we can identify what’s both upstream and downstream of β-catenin we might be able to come up with attractive drug targets to activate this pathway and promote resilience.”

If we treat a third-order symptom, the signaling molecule, everything will be alright?

Which leads me to ask:

http://www.pnas.org/content/112/8/2557.full “Brain 5-HT deficiency increases stress vulnerability and impairs antidepressant responses following psychosocial stress”

Is it science, or is it a silly and sad farce when researchers “make up” missing data?

gettingwell4 < 0 Detracted from science, Brain development, Epigenetics, Hippocampus, Limbic system, Stress , , ,

This 2014 French study was a parody of science.

The researchers “made up” missing data on over 50% of the men and over 47% of the women! All to satisfy their model that drove an agenda of the effects of adverse childhood experiences.

As an example of how silly and sad this was:

  • Two of the seven subject ages of interest were 23 and 33 consecutively, and
  • One of the nine factors was education level.

If I was a subject, and wasn’t around to give data at age 33 and later, how would the researchers have extrapolated a measurement of my education level of “high school” at age 23?

I’m pretty sure their imputation method would have “made up” education level data points for me of “high school” for ages 33 and beyond. I doubt that the model would have produced my actual education levels of a Bachelors and two Masters degrees at age 33.

Everything I said about the Problematic research on stress that will never make a contribution toward advancing science study applied to this study, including the “allostatic load” buzzword and the same compliant reviewer.

Studies like this both detract from science and are a misallocation of scarce resources. Their design and data aren’t able to reach levels where they can provide etiologic evidence.

Such studies also have limiting effects on how we “do something” about real problems, because the researchers won’t be permitted to produce findings that aren’t politically correct.

http://www.pnas.org/content/112/7/E738.full “Adverse childhood experiences and physiological wear-and-tear in midlife: Findings from the 1958 British birth cohort”