Serotonin Receptors May Be Linked to Spirituality

[Whitney]

I found this when googling for something unrelated and thought it was interesting.  The article is a few years old so there may have been further studies since it was published.

An openness to spiritual experiences may be biologically grounded in the number of serotonin receptors a person has in his or her brain. . .
. . .The self-transcendence trait in turn reflects a religious outlook versus material rationalism. . .
. . .The investigators found that the number of serotonin receptors correlated significantly and inversely with subjects’ scores for self-transcendenceâ€"the higher the score on self-transcendence, the fewer the number of receptors in all brain areas scrutinized. . .  

Full Text:
http://pn.psychiatryonline.org/cgi/content/full/39/1/33

[LARA]

Interesting.   If you have two people and the extracellular serotonin levels were equal between two individuals, fewer receptors would receive a high signal in the self-transcendent folks and more would receive a low signal in the materialist-rationalist.  Without knowing the comparative levels of serotonin in the individuals as well as the number of receptors it's hard to say how serotonin affects them by number of receptors, I would say.  

 I also have to wonder how SSRIs affect this system.  Prozac anyone?

[curiosityandthecat]

I've always thought it was connected. Same way the "religious center" of the brain is the same area that fires in some grand mal epileptic seizures, causing people to have intense spiritual experiences or even visions of God. Man, I love neuroscience.

[Squid]

I have this article and it is interesting but I feel only part of a more complex characteristic of humans.  Some excerpts from the article (which is free to download btw if anyone wants it):

A role for the serotonin system was suggested early on from subjective experiences induced by mind-altering drugs, such as LSD and psilocybin.
     Central serotonergic neurons originate from the raphe nuclei in the brainstem and innervate major brain regions, such as the hypothalamus, the limbic system, the striatum, and the neocortex.  Fourteen serotonin receptor subtypes have thus far been identified in the human brain.

A specific autoreceptor seems to be the active one in this study and proposed to be the active one affecting spiritual experience.

Presynaptic 5-HT 1A autoreceptors are highly concentrated on cell bodies in the raphe and mediate the inhibition of cell firing and serotonin release in all projection areas.  Thus the 5-ht 1A receptor may have a role as general regulator of serotonergic activity.

The values for binding potential correlated significantly with the self-transcendence dimension but not with any of the other six Temperament and Character Inventory dimensions.  The self-transcendence dimension is a composite of three distinct subscales that describe aspects of spirituality.
     Scores for spiritual acceptance versus material rationalism correlated significantly with 5-HT 1A binding potential for all three regions.

The appearence of the correlation on the one scale shows a concentration and therefore a link to the activity.

The self-transcendence dimension consists of three subscales representing several aspects of religious behavior, subjective experience, and individual worldview...we found that the correlation of self-transcendence was shown to be fully dependent on the spiritual acceptance scale.

Oddly enough, hallicnogenic drugs seem to promote the same response.

...such pharmacological effects induced by hallucinogens resemble the extrasensory perception and ideation endorsed by subjects scoring high on the spiritual acceptance scale.

So what the hell does it all mean?

These observations support the hypothesis that the physiological role of the serotonin system includes inhibition of sensory stimuli and arousal...One interpretation of the present finding is that subjects with low 5-HT 1A receptor density have sparse serotonergic innervation and thereby a weaker filtering function, allowing for increased perception and decreased inhibition.

Some other interesting things involving religiosity/spirituality:

* Similar structures go through changes when Tibetan Buddhists Meditate and Franciscan Nuns are in deep prayer (parts of their parietal cortex shows marked changes and possibly allow for a distortion of the conscious "spatial filter" which distinguishes "self" from "everything else" - hence the "feeling at one with the universe" or "greater being" sensation commonly reported)

Interested? Try reading:

Newberg, A., D'Aquili, E. and Rause, V. (2001). Why God Won't Go Away.  New York: Ballantine Books.

NOTE: While there is a lot of good content and is reader-friendly, I would have to disagree with some of the unsupported claims Dr. Newberg closes the book with.

Found this in the International Journal of Neuroscience:

Kurup, R. and Kurup, P. (2003). Hypothalamic digoxin, hemispheric chemical dominance, and spirituality. International Journal of Neuroscience, 113, 383-393.

The isoprenoid pathway was assessed in atheistic and spiritually inclined individuals.  The pathway was also assessed in individuals with differing hemispheric dominance to assess whether hemispheric dominance has a correlation with spiritual and atheistic tendency.  HMG CoA reductase activity, serum digoxin, RBC membrane Na+-K+ ATPase activity, serum magnesium, and tyrosine/tryptophan catabolic patterns were assessed in spiritual/atheistic individuals and in those differing hemispheric dominance.  In spiritually-inclined individuals, there was increased digoxin synthesis, decreased membrane Na+-K+ ATPase activity, increased tryptophan catabolites (serotonin, quinolinic acid, and nicotine), and decreased tyrosine catabolites (dopamine, noradrenaline, and morphine).  The pattern in spiritually-inclined individuals correlated with right hemispheric chemical dominance.  In atheistic individuals there was decreased digoxin synthesis, increased membrane Na+-K+ ATPase activity, decreased tryptophan catabolites, quinolinic acid, and nicotine), and increased tyrosine catabolites (dopamine, noradrenaline, and morphine).  This pattern in atheistic individuals correlated with that obtained in the left hemispheric chemical dominance.  Hemispheric chemical dominance could regulate the predisposition to spirituality or atheism.

Interesting enough, okay what are they getting at?  Well:

Spirituality is one of the most evolved of human emotions.  Spiritual tendencies have been related to temporal lobe epileptic phenomena.  Previous studies have demonstrated Na+-K+ ATPase inhibition and elevated levels of an endogenous inhibitor of membrane Na+-K+ ATPase in seizure disorder.  Digoxin is as steroidal glycoside and is reported to be synthesized by the human hypothalamus via the isoprenoid pathway.  Digoxin can modulate the neuronal membrane transport of amino acids and can regulate synaptic transmission.  Therefore, it was considered pertinent to study the digoxin synthesis and neurotransmitter patterns in individuals who are spiritually inclined or atheistic.  Since digoxin can regulate multiple neurotransmitter systems, it could also play a role in the genesis of cerebral dominance.

So....

Digoxin can inhibit membrane Na+-K+ ATPase activity.  Membrane Na+-K+ ATPase inhibition can lead to an increase in intracellular calcium and a reduction in intracellular magnesium.  Inhibition of Na+-K+ ATPase can also result in defective neuronal membrane repolarization and a paroxysmal deplarization shift resulting in epieptogenesis.  Temporal lobe epileptic phenomena have been documented in spiritually inclined individuals...The low levels of dopamine and morphine in spiritually-inclined individuals leads to a detached behavior important in spiritual evolution.  The increased serotonin levels documented here is also significant, as serotonin is a positive modulator of the excitotoxic NMDA receptor and could contribute to temporal lobe epileptogenesis.

While all this is interesting, the problem is in the small group.  Only 15 individuals were utilized for this research.  A larger group study would be in order and with other variables such as cultural differences represented but the basis of spiritual or non-spiritual maintained.  I will continue to be on the lookout for other studies that might validate or contradict this.

D’Onofrio, M., Eaves, L., Murrelle, L., Maes, H., Spilka, B. Journal of Personality 67:6,
December 1999:

Although the transmission of religiousness has been assumed to be purely cultural, behavior genetic studies have demonstrated that genetic factors play a role in the individual differences in some religious traits.

In the layman world, it is mostly assumed to be purely a product of environment whether or not certain religious behaviors are adopted.  On the most part as for: what denomination, religious or spiritual, etc (the smaller deviance), environment showed to be the dominant determinant.

In a 1986 study of two large samples of adult twins:

...found that significant contributions to social attitudes related to observance of the Sabbath, divine law, authority of the church, and truthfulness of the Bible were made by both additive and genetic effects and the shared environment.  Heritability estimates ranged from .22
to .35 and estimates for the influence of the shared environment ranged from .18 to .34 for the individual items, illustrating that familial correlations in these domains are influenced by genetic factors as well as the environment.

As for the section of religious behavior and salience:

Although slight genetic component is found in females, genetic factors do not play a role
in the church attendance of males.

and in summary:

...family resemblance in religious affiliation appears to be primarily cultural as might be expected, whereas religious attitudes and behaviors seem to be influenced by additive genetic effects as well as the shared and unshared environment.  Sociological and behavior research on the transmission or inheritance of religious beliefs and practices can no longer ignore genetic influences.

So this might lead one to suppose that such religious tendencies might be part of a certain personality, however:

The correlations with personality are all small, mostly less than 0.1.  Thus there is very little reason to suppose that church attendance reflects personality much, in so far as Eysensck’s measures capture the essentials contours of the human personality.

Although one correlation did stand out:

...the Religious Right factor is more strongly associated with these factors â€" a moderate negative correlation (-0.23 and -0.23) with “unselfish” fiscal attitudes related to issues of taxation, a moderate positive correlation with promilitary attitudes (0.33 and 0.35), and a
moderate negative correlation with Democratic versus Republican political ideology (-0.20 and -0.19), meaning that they are more likely to espouse those tenets associated with being Republican

Which tells us empirically what we’ve known for a while socially.  

Also, the findings see that:

...it is obvious that religion is, at most, only partly a function of the personality dimensions..

In summation:

Religious behaviors and attitudes...such as church attendance and the tendency to espouse more conservative religious values, including some of those normally espoused by the Religious Right, show varying degrees of genetic inheritance beyond that provided by the family environment and assortative mating...the largest single component of variance is that due to the environmental differences among members of the same family...there is a larger genetic component contributing to church attendance and Religious Right social attitudes in women, driven mostly by the nonadditive genetic effects...the larger correlations between relatives for religious behaviors and attitudes display a much greater nongenetic component...the correlations between mates for religious behavior and attitudes are among the largest known, comparable to and even exceeding those for monozygotic twins.  This correlation significantly adds to the genetic component of church attendance and the Religious Right factor.

The study was conducted utilizing a sample of 14,781 twins (in Virginia) and their family members, including their parents, spouses, children, and siblings.  Almost all were Caucasian (99.8%).  Of those, most were Protestant (65.8%) followed by Catholic, Jewish and finally by the
“unspecified”.  Their personality domains were based on short scales using the Eysenck Personality Questionnaire with the help of Dr. Eysenck.

Found some other interesting views into the neurofunctioning of the 'religious' mind.  From the European Journal of Neuroscience:

Nina P. Azari et tal.  "Short Communication: Neural correlates of religious experience"  European Journal of Neuroscience Vol. 13  2001.

The subjects tested were of the "Free Evangelical Fundamentalist Community" in Germany.  They all had supposedly had a documented religious experience.  They also all interpret biblical text literally.  Anyway, here's a synopsis of the findings:

We studied a group  of self-identified religious subjects, who attributed their religious experiences to a biblical psalm, in order to explore for the first time using functional neuroimaging the brain areas involved in religious experience.  While the view that religious experience is a preconceptual feeling would predict the activation of limbic brain areas engaged by emotion, attribution theory would predict brain areas mediating reasoning to be activated.  We show that, during religious recitation, religious subjects activated a frontal-parietal circuit composed of the dorsolateral prefrontal, drosomedial frontal and medial parietal cortex, suggesting that religious experience may be a cognitive process.

And furthermore:

Recent neuropsychological and functional imaging studies suggest that the prefrontal cortex holds representations of knowledge structured in the form of cognitive schemas.  Cognitive schemas are mental representations containing organized prior knowledge about specific domains, inclusive of specifications of the causal relations among the attributes therein.  Religious attributions are made in accordance with religious schemas, which consist in organized knowledge about religion and religious issues, and include reinforced structures for inferring religiously related causality of experience events.

Contrary to what others have found surrounding the activation of the limbic system and emotional centers of the brain, these researchers found:

...the religious experience was not an emotional experience, nor an arousal comparable to that of the happy state which we observed in the non-religious subjects [when the participates were read from a children's book]...A challenge for the future work will be to explore transient religious states and the evolution of other varieties of religious experience.  It may turn out that 'religious experience' can be divided eventually into a variety of subprocesses as has been, for example, with memory.

I tend to agree with their last speculation.  Although, further research is needed.

There's also an interesting finding about infrasound and it's effects on people:

http://news.bbc.co.uk/2/hi/science/nature/3087674.stm

An experiment was carried out during an concert which seems to support the idea that this range of frequencies can elicit "strange" feelings in people which may be misinterpreted:

http://www.spacedog.biz/Infrasonic/results.htm




The brain sciences are beginning to discover some interesting things about religiosity and spirituality and the more that seems to be found, the less supernatural it all seems to be.  But I'm sure the usual retort of those who would disagree would be something like:

[homer simpson]...stupid science...[/homer simpson]

[LARA]

Now that is an informational overload.  I'll be Googling for a while.

A few things strike me here.

The variety and localization of types of serotonin receptors.

The fact that this system is in constant flux with states of mind.  (Buddhists in meditation example)

So my question is how do experimenters actually measure this stuff?  Decapitate hippies on LSD en masse, slice up their brains and put the layers on slides for labeling with specific markers?  I mean it's not like spitting in a cup or anything.  I would think you'd have to do something like radioactive markers specific to each receptor type and then do something like a MRI or similar procedure to map the locations.  Then I can't even imagine trying to deal with the resolution issues and determine which spots were glowing harder.  Plus procedures like that probably get pricey, so I can guess at why there are only 15 or so subjects tested in an experiment.  Then there would be the issue of creating a reliable system to assess the self-transcendence of the individual.  I imagine it would be very complex.

Interesting stuff, nonetheless.

[Will]

I volunteer to be a part of the control group for the next, larger round of studies!

Seriously, this has the potential to be huge. I hope they can continue to study this.

[monkeyNutBread]

Oh wow. I must have a low amount of serotonin receptors.