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In this essay, His Holiness the 14th Dalai Lama addresses the question, “What possible benefit could there be for a scientific discipline such as neuroscience in engaging in dialogue with Buddhist contemplative tradition?”
In this essay, His Holiness the 14th Dalai Lama addresses the question, “What possible benefit could there be for a scientific discipline such as neuroscience in engaging in dialogue with Buddhist contemplative tradition?”
Posted in Mindfulness | Tagged Brain, Buddism, Dalai Lama, Meditation, Nervous system, Neuron, spirituality, Teachers and Centers | Leave a Comment »

Some of the most epic and beautiful of the yoga sutras are found in the final book IV. One of them popped into mind when I came across a recent neuroscience report entitled, “Predicting Persuasion-Induced Behavior Change from the Brain” by Emily Falk and colleagues at the Department of Psychology at the University of California, Los Angeles. [DOI:10.1523/JNEUROSCI.0063-10.2010]. Here, a research team asks if there are places in the brain that encode future – yes, future actions. More specifically, they asked 20 volunteers to lay in an MRI scanner and listen/view a series of messages on the benefits and importance of sunscreen. Then, 1-week later, they inquired about the frequency of sunscreen use. It turns out that sunscreen use did increase (suggesting the subjects read the messages), but more interestingly, that there were correlations in brain activity (in several regions of the brain) with the degree of increased sunscreen use. That is, some individuals recorded a bit of brain activity that predicted their future use of sunscreen.
Very neat indeed! although, there are likely many reasons to remain skeptical. This is because the brain is a very complex system and, with so much going on inside, its likely anyone could find correlations in activity with any-old “something” and “some area of the brain” if they looked hard enough. In this article however, the authors had preselected their brain regions of interest – the medial frontal cortex and the precuneus – since another group had shown that activity in these regions were able to predict future actions (on the order of a few seconds). Thus, the research team was not looking for any willy-nilly correlation, but for a specific type of interaction between the brain and future action (this time on the order of weeks).
The particular ancient sutra that may have some poetic tie-ins here is IV.12 atita anagatam svarupatah asti adhvabhedat dharmanam “the existence of the past and future is as real as that of the present. As moments roll into movements which have yet to appear as the future, the quality of knowledge in one’s intellect and consciousness is affected.”
Might there be neural traces predicting one future actions? This research makes it seem possible. Are these traces accessible to ordinary folks or advanced meditators? Who knows. As always, the joy lies in trying to find out and trying to reach ever deeper states of harmony and unity. One thing I found intriguing was that the research team picked the medial prefrontal cortex and the precuneus because these brain regions,
“are reliably co-activated across a host of “self” processes and the extent to which people perceive persuasive messages to be self-relevant has long been thought to play a part in attitude and behavioral change”.
Certainly, when something feels relevant to “me” and reinforces my own “self” image, I’m more prone to remember and act upon it. Yoga, for example! I hope I’m encoding signals now that will predict my attendance in class this week!
Posted in Uncategorized | Tagged B. K. S. Iyengar, Brain, Central nervous system, Consciousness, frontal cortex, Human, Meditation, Mind, Neuron, Patañjali, philosophy, precuneus, Religion and Spirituality, Yoga, Yoga Sutras of Patanjali | Leave a Comment »
The painter Paul Cezanne is oft remembered as an extremely focused artist who deeply scrutinized and meditated upon his subjects. “The day is coming when a single carrot, freshly observed, will set off a revolution.”, he once said, as well as, “With an apple I will astonish Paris.” His work tried not to capture an object as seen by the naked eye, but rather to capture the momentary experience of an object that is perceived by a thinking, feeling individual. “For an Impressionist to paint from nature is not to paint the subject, but to realize sensations”, seems to capture his effort to use painting to capture his deep inward and outward reflections of everyday life.
In some ways, this reminds me of yoga, when, with much practice, one becomes more adept at paying attention to specific details in time and space and reflecting deeply upon one’s inner reactions to the outer world. I thought that one of Patanjali’s yoga sutras, “Yoga is the cessation of movements in the consciousness.” (I.2) sounded a lot like the master painter patiently working alongside a river who said, “Here, on the river’s verge, I could be busy for months without changing my place, simply leaning a little more to right or left.”
With this in mind, I dug into a few quotes from Paul Cezanne and ran them past some of Patanjali‘s yoga aphorisms. I think both Patanjali and Cezanne were working very hard at being present and mindful in the moment and trying to unify their outward and inward experiences – one through yoga and one through painting! Here are a few selected quote pairs with Cezanne on top and Pataljali below:
“Cezanne”
“Patanjali”
“When I judge art, I take my painting and put it next to a God made object like a tree or flower. If it clashes, it is not art.”
“When consciousness dissolves in nature, it loses all marks and becomes pure.” (I.45)
“A puny body weakens the soul.”
“Asana is perfect firmness of body, steadiness of intelligence and benevolence of spirit” (II.46)
“Right now a moment of time is passing by! We must become that moment.”
“Study of the silent moments between rising and restraining subliminal impressions is the transformation of consciousness towards restraint.” (III.9)
“The artist makes things concrete and gives them individuality.”
“Constructed or created mind springs from the sense of individuality” (IV.4)
“There are two things in the painter, the eye and the mind; each of them should aid the other.”
“Consciousness distinguishes its own awareness and intelligence when it reflects and identifies its source – the changeless seer – and assumes his form.” (IV.22)
“Optics, developing in us through study, teach us to see.”
“An object remains known or unknown according to the conditioning or expectation of the consciousness.” (IV.17)
“If isolation tempers the strong, it is the stumbling-block of the uncertain.”
“Practice and detachment are the means to still the movements of consciousness” (I.12)
“I could paint for a hundred years, a thousand years without stopping and I would still feel as though I knew nothing.”
“When the object of meditation engulfs the meditator, appearing as the subject, self-awareness is lost. This is samadhi.” (III.3)
“Don’t be an art critic, but paint, there lies salvation”
“Practice is the steadfast effort to still these fluctuations.” (I.13)
Posted in artist, Mindfulness | Tagged Consciousness, dualism, Meditation, Mind, Patañjali, Paul Cézanne, Practice, Religion and Spirituality, Yoga, Yoga Sutras of Patanjali | Leave a Comment »
This post belongs to an ongoing exploration of mindfulness biology.
On February 27, 2009 a letter appeared in Science Magazine entitled, “Neuroscience and the Soul” (and covered here). An heavy topic – even for a science journal! and much to explore down the road as the cross-informing synthesis of genetics and neuroscience continues.
As it turns out, I’m enjoying some summer reading of Jonah Lehrer‘s Proust Was A Neuroscientist and chapter 1 does not disappoint! It covers the life and poetry of Walt Whitman who was among the first modern western artists to reject dualist notions of a dichotomy between mind and body that stemmed from early Christian writings and from the philosophies of Rene Descartes (1641). Whitman, rather, embraced longstanding eastern notions of a synthesis and continuity of the mind and body. Whitman’s poem, I Sing The Body Electric captures some of his youthful ardor for the human body and the human condition. Just 2 lines from Chapter 1, line 10:
“And if the body does not do fully as much as the soul? And if the body were not the soul, what is the soul?”
Ideas with such eastern influence earned him accolades as, “a remarkable mixture of the Bhagavad Ghita and the New York Herald” in his contemporary 1850’s press. Lehrer also traces the birth of modern neuroscience to early pioneers such as the psychologist William James, who, it turns out, was a great admirer of Whitman’s poetry.
So it seems that the “Neuroscience and the Soul” debate continues … from a wrong turn with Descartes in the 1600’s, steered back on track by Whitman and James in the 1850’s? Where will the genome lead us?
Posted in Mindfulness | Tagged Poetry, Walt Whitman, William James | 1 Comment »

This post is part of an ongoing exploration of “mindfulness” biology and the neurobiology of reflecting inwardly on one’s mental life. I hope it helps support the self-discovery aim of the blog.
In some ways, the 8 limbs of yoga described in the yoga sutras, seem a bit like a ladder, rather than a concentric set of outreached arms or spokes on a wheel. As I practice this form of postures and mindfulness, it seems like I’m working toward something. But what? I certainly feel healthier, and also enjoy the satisfaction of getting slightly more able (ever so slightly) to shift into new postures – so am quite motivated to continue the pursuit. Perhaps this is how yoga got started eons ago? Just a pursuit that – by trial and error – left its practitioners feeling more healthy, relaxed and more in touch with their outer and inner worlds? But where does this path lead, if anywhere?
I was intrigued by a report published in 1973 by an 8-day study carried out on the grounds of the Ravindra Nath Tagore Medical College and Hospital, Udaipur, India and subsequent letter, “The Yogic claim of voluntary control over the heart beat: an unusual demonstration” published in the American Heart Journal, Volume 86 Number 2. Apparently, a local yogi named Yogi Satyamurti:
Yogi Satyamurti, a sparsely built man of about 60 years of age, remained confined in a small underground pit for 8 days in what according to him was a state of “Samadhi,” or deep meditation, with all bodily activity cut down to the barest minimum.
The medical researchers had the yogi’s heart and other physiological functions under constant watch via electrical recording leads, and watched as the yogi’s heart slowed down (their equipment registered a flatline) a remained so for several days. Upon opening up the pit, the researchers found:
The Yogi was found sitting in the same posture. One of us immediately went in to examine him. He was in a stuporous condition and was very cold (oral temperature was 34.8O C) [the same temperature as the earth around him].
After a few hours, the yogi had recovered from the experience and displayed normal physiological and behavioral function – despite 8 days underground (air supposedly seeped in from the sides of the pit) with no food or human contact!
An amazing feat indeed – one that has some scientists wondering about the psychology and physiology that occurs when advanced meditators sink into (very deep) states. John Ding-E Young and Eugene Taylor explored this in an article entitled, “Meditation as a Voluntary Hypometabolic State of Biological Estivation” published in News Physiol. Sci., Volume 13, June 1998. They suggest that humans have a kind of latent capacity to enter a kind of dormant or hibernation-like state that is similar to other mammals and even certain primates.
Meditation, a wakeful hypometabolic state of parasympathetic dominance, is compared with other hypometabolic conditions, such as sleep, hypnosis, and the torpor of hibernation. We conclude that there are many analogies between the physiology of long-term meditators and hibernators across the phylogenetic scale. These analogies further reinforce the idea that plasticity of consciousness remains a key factor in successful biological adaptation.
Practice, practice, practice – towards an ability to engage a latent evolutionary adaptation? Such an adaptation – in humans – sounds hokey, but certainly an interesting idea worth exploring more in the future.
Posted in Mindfulness | Tagged Brain, Cognition, Meditation, Psychology, Religion and Spirituality, Yoga | Leave a Comment »

Like many folks, I generally feel better ever since I started practicing yoga. Outwardly, my body is (slowly) growing stronger and more flexible and perhaps (hopefully) soon, I’ll even lose a few pounds. However, even if I was to convince myself that looked slimmer (skinny mirrors?), the only way to really know if I’ve lost weight, is to stand on a scale and record my weight each day (darn! no fatness lost so far).
That takes care of the body right – but what about the inner, emotional improvements I might be experiencing? How to measure these?
Here are some mobile- and web-based tools to help one track one’s emotions. Most of these websites, like Moodstats, Track Your Happiness, MoodJam, MoodMill, Finding Optimism and MoodLog seem to function as online diaries which keep a running tab on aspects of ones moods and emotions. Perhaps such tools – if used over long durations – would enable one to verify a shift toward a less anxious and more contented inner feeling? I don’t know.
Perhaps the real proof of “inner” progress would be that I had closed my computer and put away my mobile device and, rather, was outside enjoying the sights and sounds of nature. Perhaps best to avoid mixing yoga and digital distractions.
Posted in Mindfulness | Tagged B. K. S. Iyengar, Breathing, Buddism, Central nervous system, Consciousness, dualism, Emotion, Health, Human, India, informatics, Meditation, mindfulness, Mood, Nervous system, Neuron, parasympathetic nervous system, Patañjali, Personalized medicine, philosophy, Religion and Spirituality, Shopping, spirituality, Yoga | Leave a Comment »
I’m enjoying some summer reading of Jonah Lehrer‘s Proust Was A Neuroscientist. Chapter 1 does not disappoint! – on the life and poetry of Walt Whitman who was among the first modern western artists to reject dualist notions of a dichotomy between mind and body that stemmed from early Christian writings and the philosophies of Rene Descartes (1641), and rather, embrace longstanding eastern notions of a synthesis and continuity of the mind and body.
This may relate to the ancient yoga sutra II.48 tatah dvandvah anabhighatah “from then on (after the perfection of asanasa), that sadhaka (yoga student) is undisturbed by dualities”.
Whitman’s poem, I Sing The Body Electric captures some of his youthful ardor for the unified human body-soul and the human condition. Just 2 lines from Chapter 1, line 10:
“And if the body does not do fully as much as the soul?
And if the body were not the soul, what is the soul?”
Ideas with such eastern influence earned him accolades as, “a remarkable mixture of the Bhagavad Ghita and the New York Herald” in his contemporary 1850’s press. Lehrer also traces the birth of modern neuroscience to early pioneers such as the psychologist William James, who, it turns out, was a great admirer of Whitman’s poetry.
A wrong turn with Descartes in the 1600’s, steered back on track by Whitman and James in the 1850’s!
Posted in Mindfulness | Tagged Arts, B. K. S. Iyengar, Breathing, Buddism, Central nervous system, Consciousness, Emotion, India, Jonah Lehrer, Meditation, mindfulness, New York Herald, Patañjali, philosophy, Poetry, Proust Was A Neuroscientist, Psychology, relaxation, Religion and Spirituality, soul, Walt Whitman, William James, World Literature, Yoga, Yoga Sutras of Patanjali | Leave a Comment »
Husband: Darling, I wish you would stop marketing the results of clinical trials for medications that you know have mainly placebo effects with no side effect.
Wife: Dear, you are missing the point. The placebo lets us know that there is still something magical inside of us … something that hasn’t been educated-out, or televisioned-out, or churched-out, or spanked-out. Even when we know exactly how that whole experience is going to play out, it is still fun to play along. Do you know what I mean?
Husband: Wait, are we talking about experimercials?
Posted in Uncategorized | Tagged placebo | Leave a Comment »
![03.23.09 [#082] Yogurt Reach 03.23.09 [#082] Yogurt Reach](https://i0.wp.com/farm4.static.flickr.com/3637/3380481129_c6ec64c9d8_m.jpg)
Pity the poor brain. What a job it has! Did you know that just to reach into a refrigerator and grab a glass of milk, involves at least 50 or so key muscles in the hand, arm and shoulder which can, in principle, lead to over 1,000,000,000,000,000 possible combinations of muscle contractions? Just so you know, this is 1,000 times MORE contraction possibilities than there are neurons in the brain (only a mere 1,000,000,000,000 neurons). I’m sorry brain, I’ll keep my hands out of the fridge, I promise!
To accomplish this computational feat, Rodolfo R. Llinas and Sisir Roy in their paper entitled, “The ‘prediction imperative’ as the basis for self-awareness” [doi:10.1098/rstb.2008.0309] suggest that brain has evolved a number of strategies.
For starters, the authors point out that the brain can lower the computational workload of controlling motor output by sending motor control signals in a non-continuous and pulsatile fashion.
“We see that the underlying nature of movement is not smooth and continuous as our voluntary movements overtly appear; rather, the execution of movement is a discontinuous series of muscle twitches, the periodicity of which is highly regular.”
This computational strategy has the added benefit of making it easier to bind and synchronize motor-movement signals with a constant flow of sensory input:
“a periodic control system may allow for input and output to be bound in time; in other words, this type of control system might enhance the ability of sensory inputs and descending motor command/controls to be integrated within the functioning motor apparatus as a whole.“
Another strategy is the use of memory for the purposes of prediction (actually, their paper is part of a special theme issue from the Philosophical Transactions of the Royal Society B entitled, Predictions in the brain: using our past to prepare for the future). The authors describe the way in which neural circuits in the body and brain are inherently good at learning and storing information which makes them very good at using that information for making predictions and pre-prepared plans for what to do with expected incoming sensory inputs. These neural mechanisms may also help reduce computational loads associated with moving and coordinating the body. Interestingly, the authors note,
“while prediction is localized in the CNS, it is a distributed function and does not have a single location within the brain. What is the repository of predictive function? The answer lies in what we call the self, i.e. the self is the centralization of the predictive imperative. The self is not born out of the realm of consciousness—only the noticing of it is (i.e. self-awareness).” Here’s a link to Llinas’ book on where the “self” resides.
Lastly, the authors suggest that the genome might encode certain structural and functional aspects of neural development that create a bias for certain types of computation and prime neural networks with a Bayesian type of prior knowledge. Their idea is akin to an organism being “experience expectant” rather than a pure blank slate that has to learn every stimulus-response contingency by trial-and-error. To support their notion of the role of the genome, the authors cite a 2003 study from the Yonas Lab on the development of depth perception. Another related study is covered here.
Methinks that genetic variants might someday be understood in terms of how they bias computational processes. Something to shoot for in the decades to come!
Posted in Mindfulness, Visual cortex | Tagged Cognition, Computation, Development, Neural network | 2 Comments »

One of the themes that emerges in I.I atha yoganusasanam, and runs throughout the yoga sutras, is the notion that a yoga practice will bring one into a deeper awareness of the self. To begin to explore the modern science notion of self-awareness, here’s a 2009 paper entitled, “The ‘prediction imperative’ as the basis for self-awareness” by Rodolfo R. Llinas and Sisir Roy [doi:10.1098/rstb.2008.0309]. The paper is part of a special theme issue from the Philosophical Transactions of the Royal Society B with the wonderfully karmic title: Predictions in the brain: using our past to prepare for the future.
Without unpacking the whole (open access) article, here are a few ideas that seem to connect loosely to themes in yoga.
The main issue addressed by the authors is how the brain manages to solve the computational problem of movement. Here’s the problem: to just, for example, reach into a refrigerator and grab a carton of milk (a far cry from, say, scorpion pose) they point out that,
“there are 50 or so key muscles in the hand, arm and shoulder that one uses to reach for the milk carton (leading to) over 1,000,000,000,000,000 combinations of muscle contractions (that) are possible.”
Yikes! that is an overwhelming computational problem for the brain to solve – especially when there are 1,000-times FEWER neurons in the entire brain (only a mere 1,000,000,000,000 neurons). To accomplish this computational feat, the authors suggest that brain has evolved 2 main strategies.
Firstly, the authors point out that the brain can lower the computational workload of controlling movement (motor output) by sending motor control signals in a non-continuous and pulsatile fashion.
“We see that the underlying nature of movement is not smooth and continuous as our voluntary movements overtly appear; rather, the execution of movement is a discontinuous series of muscle twitches, the periodicity of which is highly regular.”
This computational strategy has the added benefit of making it easier to bind and synchronize motor-movement signals with a constant flow of sensory input:
“a periodic control system may allow for input and output to be bound in time; in other words, this type of control system might enhance the ability of sensory inputs and descending motor command/controls to be integrated within the functioning motor apparatus as a whole.”
The idea of synchronizing sensory information with pulsing motor control signals brings to mind more poetic notions of rhythmicity and the way that yogis use their breath to enhance and unify their outer and inner world experience. Neat! Also, I very much like the idea that our brains have enormously complex computational tasks to perform, so I’m keen to do what I can to help out my central nervous system. Much gratitude to you brain!
Secondly, the authors then move ahead to describe the way in which neural circuits in the body and brain are inherently good at learning and storing information which makes them very good at predicting what to do with incoming sensory inputs. This may just be another strategy the brain has evolved to simplify the enormous computational load associated with moving and coordinating the body. Interestingly, the authors note,
“while prediction is localized in the CNS, it is a distributed function and does not have a single location within the brain. What is the repository of predictive function? The answer lies in what we call the self, i.e. the self is the centralization of the predictive imperative. The self is not born out of the realm of consciousness—only the noticing of it is (i.e. self-awareness).” Here’s a link to Llinas’ book on this topic.
The “self” is not just in the brain? but distributed throughout the entire CNS? Whoa! Much to explore here. Many thematic tie-ins with ancient Vedic notions of self and consciousness … will explore this in the future!
One last passage I found of interest was written by Moshe Bar, the editor of the special issue, who suggested that neural solutions to these inherent computational challenges make the brain/mind a naturally restless place. His words,
“As is evident from the collection of articles presented in this issue, the brain might be similarly flexible and ‘restless’ by default. This restlessness does not reflect random activity that is there merely for the sake of remaining active, but, instead, it reflects the ongoing generation of predictions, which relies on memory and enhances our interaction with and adjustment to the demanding environment.”
My yoga teachers often remind me that “monkey mind” is normal and with more practice, it will subside. Very cool to see a tie-in with modern research.
Posted in breathing | Tagged B. K. S. Iyengar, Brain, Central nervous system, coherence, Consciousness, dualism, Input/output, Meditation, Mind, mindfulness, Nervous system, Neuron, Philosophical Transactions of the Royal Society, philosophy, Psychology, relaxation, Religion and Spirituality, Rodolfo R. Llinas, spirituality, Yoga | 2 Comments »
According to B.K.S. Iyengar, in his book, “Light on the Yoga Sutras of Patanjali“, the first chapter of Patanjali‘s yoga sutras – samadhi pada – deals with movements of consciousness, or citta vrtti.
Specifically, the very first chapter, first sutra: I.I atha yoganusasanam, “With prayers for divine blessings, now begins an exposition of the sacred art of yoga”. Iyengar expands on this to suggest that Patanjali is inviting the reader to begin an exploration of that hidden part of man that is beyond the senses.
Beautifully said. Indeed, as a new student, I’ve noticed my own awareness of my body, my emotions and my thought processes has increased. I’m not sure if this is what Patanjali had in mind, but I’m finding that aspects of my physical and mental life that were hidden are now more apparent to me. It feels good.
How does this work, and what might types of brain mechanisms are involved in gaining self awareness? What is the self anyway? What is self-awareness? How far into one’s unconscious mental processes can one’s self-awareness reach? Why does it feel good to have more self-awareness? Lot’s to ponder in follow-ups to come.
Even though the sutras were written more than 2,000 years ago, a neural- and brain-based understanding of consciousness remains a topic of debate and intense research. I’ll do my best to explore some of this research and ways in which it might reflect back to the poetic and admittedly broad notions of consciousness in the yoga sutras.
Posted in self-awareness | Tagged B. K. S. Iyengar, Brain, Central nervous system, Consciousness, Emotion, Mind, mindfulness, Patañjali, Psychology, Religion and Spirituality, Yoga, Yoga Sutras of Patanjali | Leave a Comment »
pointer to the NOVA program on epigenetics “Ghost in Your Genes” (YouTube link here). Fantastic footage. Great intro to epigenetics and so-called trans-generational effects and the inheritance of epigenetic marks – which, in some cases – are left by adverse or stressful experience. A weird, wild, game-changing concept indeed – that my grandchildren could inherit epigenetic changes induced in my genome by adverse experience.
Posted in Uncategorized | Tagged Add new tag, Biology, Epigenetics, Gene expression, NOVA | 1 Comment »

just a pointer to: Genetic Future’s pointer to the recent article, “Family become first to have DNA sequenced for non-medical reasons“. The father suggests, “it will be ethically improper if you don’t have your children sequenced“.
Early days.
Posted in Uncategorized | Tagged DNA, Genetic testing, Genetics, genome sequencing, Personalized medicine | Leave a Comment »
Posted in Uncategorized | Tagged Art, meme-art | Leave a Comment »

In an earlier post on Williams Syndrome, we delved into the notion that sometimes a genetic variant can lead to enhanced function – such as certain social behaviors in the case of WS. A mechanism that is thought to underlie this phenomenon has to do with the way in which information processing in the brain is widely distributed and that sometimes a gene variant can impact one processing pathway, while leaving another pathway intact, or even upregulated. In the case of Williams Syndrome a relatively intact ventral stream (“what”) processing but disrupted dorsal stream (“where”) processing leads to weaker projections to the frontal cortex and amygdala which may facilitate gregarious and prosocial (a lack of fear and inhibition) behavior. Other developmental disabilities may differentially disrupt these 2 visual information processing pathways. For instance, developmental dyspraxia contrasts with WS as it differentially disrupts the ventral stream processing pathway.
A recent paper by Woodcock and colleagues in their article, “Dorsal and ventral stream mediated visual processing in genetic subtypes of Prader–Willi syndrome” [doi:10.1016/j.neuropsychologia.2008.09.019] ask how another developmental disability – Prader-Willi syndrome – might differentially influence the development of these information processing pathways. PWS arises from the lack of expression (via deletion or uniparental disomy) of a cluster of paternally expressed genes in the 15q11-13 region (normally the gene on the maternally inherited chromosome is silent, or imprinted – related post here). By comparing PWS children to matched controls, the team reports evidence showing that PWS children who carry the deletion are slightly more impaired in a task that depends on the dorsal “where” pathway whilst some sparing or relative strength in the ventral “what” pathway.
Posted in Uncategorized | Tagged Brain, Conditions and Diseases, Development, Epigenetics, Frontal lobe, Gene expression, Genomic imprinting, Mutation, Prader-Willi syndrome, visual system, Williams Syndrome | Leave a Comment »
According to the authors of “Protective effect of CRHR1 gene variants on the development of adult depression following childhood maltreatment: replication and extension” [PMID: 19736354], theirs is “the first instance of Genes x Environment research that stress has been ascertained by more than 1 study using the same instrument“. The gene they speak of is the Corticotropin-releasing hormone receptor 1 (CRHR1) gene (SNPs rs7209436, rs110402, rs242924 which can form a so-called T-A-T haplotype which has been associated with protection from early life stress (as ascertained using the Childhood Trauma Questionnaire CTQ)).
The research team examined several populations of adults and, like many other studies, found that early life stress was associated with symptoms of depressive illness but, like only 1 previous study, found that the more T-A-T haplotypes a person has (0,1,or 2) the less likely they were to suffer these symptoms.
Indeed, the CRHR1 gene is an important player in a complex network of hormonal signals that regulate the way the body (specifically the hypothalamic pituitary adrenal axis) transduces the effects of stress. So it seems quite reasonable to see that individual differences in ones ability to cope with stress might correlate with genotype here. The replication seems like a major step forward in the ongoing paradigm shift from “genes as independent risk factors” to “genetic risk factors being dependent on certain environmental forces”. The authors suggest that a the protective T-A-T haplotype might play a role in the consolidation of emotional memories and that CRHR1 T-A-T carriers might have a somewhat less-efficient emotional memory consolidation (sort of preventing disturbing memories from making it into long-term storage in the first place?) – which is a very intriguing and testable hypothesis.
On a more speculative note … consider the way in which the stress responsivity of a developing child is tied to its mother’s own stress responsivity. Mom’s own secretion of CRH from the placenta is known to regulate gestational duration and thus the size, heartiness and stress responsiveness of her newborn. The genetic variations are just passed along from generation to generation and provide some protection here and there in an intertwined cycle of life.
The flowers think they gave birth to seeds,
The shoots, they gave birth to the flowers,
And the plants, they gave birth to the shoots,
So do the seeds they gave birth to plants.
You think you gave birth to the child.
None thinks they are only entrances
For the life force that passes through.
A life is not born, it passes through.
anees akbar
Posted in CRHR1, Uncategorized | Tagged Add new tag, Depression, Development, Emotion, Genetics, Hypothalamic–pituitary–adrenal axis, Major depressive disorder, Mental disorder, Mental health, Single-nucleotide polymorphism, Stress | Leave a Comment »
Twin studies have long suggested that genetic variation is a part of healthy and disordered mental life. The problem however – some 10 years now since the full genome sequence era began – has been finding the actual genes that account for this heritability.
It sounds simple on paper – just collect lots of folks with disorder X and look at their genomes in reference to a demographically matched healthy control population. Voila! whatever is different is a candidate for genetic risk. Apparently, not so.
The missing heritability problem that clouds the birth of the personal genomes era refers to the baffling inability to find enough common genetic variants that can account for the genetic risk of an illness or disorder.
There are any number of reasons for this … (i) even as any given MZ and DZ twin pair shares genetic variants that predispose them toward the similar brains and mental states, it may be the case that different MZ and DZ pairs have different types of rare genetic variation thus diluting out any similar patterns of variation when large pools of cases and controls are compared … (ii) also, the way that the environment interacts with common risk-promoting genetic variation may be quite different from person to person – making it hard to find variation that is similarly risk-promoting in large pools of cases and controls … and many others I’m sure.
One research group recently asked whether the type of common genetic variation(SNP vs. CNV) might inform the search for the missing heritability. The authors of the recent paper, “Genome-wide association study of CNVs in 16,000 cases of eight common diseases and 3,000 shared controls” [doi:10.1038/nature08979] looked at an alternative to the usual SNP markers – so called common copy number variants (CNVs) – and asked if these markers might provide a stronger accounting for genetic risk. While a number of previous papers in the mental health field have indeed shown associations with CNVs, this massive study (some 3,432 CNV probes in 2000 or so cases and 3000 controls) did not reveal an association with bipolar disorder. Furthermore, the team reports that common CNV variants are already in fairly strong linkage disequilibrium with common SNPs and so perhaps may not have reached any farther into the abyss of rare genetic variation than previous GWAS studies.
Disappointing perhaps, but a big step forward nonetheless! What will the personal genomes era look like if we all have different forms of rare genetic variation?
Posted in Chromosome structural variants, Intronic or repetitive sequences, Uncategorized | Tagged Add new tag, Biology, bipolardisorder, Copy number variation, Depression, DNA, Gene, Genetic testing, Genetic variation, Genetics, Genome-wide association study, Mental disorder, Mental health, Single-nucleotide polymorphism, Twin, Twin study | 1 Comment »