Of mice and birds

 Zebra finch genetics

The zebra finch, Taeniopygia guttata, is an Australian songbird with a black and white striped breast. It is used by neuroscientists as a model organism to study the learning and production of a complex motor behavior–birdsong. Like other songbirds[1], zebra finches are genetically predisposed to learn their species’ particular song, but they have to hear the song being produced and slowly learn to mimic it through a trial and error process, similar to how babies learn to speak.

"Hey, pretty lady. Wait, are we related?"

Zebra finches

So out of the over 5,000 identified passerine songbirds, why did neuroscience choose the zebra finch as its model songbird? For similar reasons, to why biology chose the mouse as a model mammal–zebra finches are small, easy to care for, and breed well in captivity. However, with any lab-bred animals there is a risk of inbreeding, which could alter the results of studies and effectively create subspecies reducing comparability between labs.

Lab bred animals – inbred strains of mice

To reduce genetic variability within studies and increase comparability between labs, mouse geneticists have intentionally mated strains of mice to be inbred. By breeding mice with their siblings for ten generations[2], they generated animals homozygous at essentially every allele. In other words, all of the animals born from this process have the same genome[3], with the same copies of each gene on each chromosome. These animals are essentially genetic clones of one another, and if they reproduce with each other their young will clones as well. Through this process we created standardized inbred strains of mice such as C57/BL6Js or BALB/CByJs that are used in labs around the world and maintained by organizations such as The Jackson Laboratory.

Inbred strains have been essential for research, however they can sometimes produce idiosyncratic results, that don’t generalize to other strains, let alone mammals in general. For example, knocking out a gene in one strain may have an obvious phenotype that is conspicuously absent in another, likely because other genes can compensate in the second strain. In extreme cases, inbreeding can fundamentally alter normal characteristics of the species and predispose pathological states, for example BALB/cWah1, are predisposed to lack a corpus callosum. About 20% of mice have no CC and another 20 to 30% have an unusually small CC. Scientists have therefore argued that while data generated from inbred strains might be more reproducible, it may also be less generalizable. You have reduced experimental noise and you can reproduce the same results, but are they robust findings that generalize to all mice or only a particular strain.

bieldefeld white zebra finch

Are zebra finches inbred?

There have been no efforts (to my knowledge) to generate an inbred laboratory strain of zebra finches. However, there could potentially have been bottlenecks during the process of domestication and shipping birds between continents that have reduced genetic diversity within laboratory populations of the species. To investigate the population genetics of laboratory zebra finches, researchers genotyped 1000 zebra finches from 18 laboratory populations (held in Europe, North America, and Australia), and two wild populations at 10 microsatellites. Microsatellites, are sequences of repeats of 2-5 base pairs that tend to be quite polymorphic, making them good markers for genetic diversity[4].

It's zebra finches all the way down...

Forstmeier 2007

As might be expected, laboratory populations showed loss of genetic variability, due to genetic drift. If in a population a particular allele every drifts to zero, then it is lost in that population. Lab populations on average had roughly half the number of alleles per locus compared to wild zebra finches—11.7 for captive versus 19.3 for wild. The most inbred population studied, a population bred for the recessive trait of white plumage showed only 6.4 alleles per locus, roughly a third of the alleles per locus seen in the wild populations. Researchers found genetic differences between zebra finches found in their European and North American populations and pointed out that there could be functional differences between these populations as well.

A radiation of inbreeding

Forstmeier 2007

The study looked at some functional differences between populations of zebra finches. Populations varied greatly in body mass, with some laboratory populations weighing almost double that of newly domesticated populations (and although body mass may be affected by animal husbandry and housing, this result was true even for three genetic separate populations housed in the same lab). Body weight of animals can be important for scientists who may wish to place electrodes, cannuli, or other devices on birds heads, but it was mainly used as an easy and reliable measure to show real differences between the populations. It is possible there are differences to brain structures and genes involved in learning and plasticity that may affect song structure as well. Such differences are more difficult to demonstrate, but also important to know as they could affect and possibly complicate results from studies.

In sum, the laboratory populations studied zebra finches are somewhat inbred, but still show diversity. If studies conflict between North American and European laboratories, we should consider if genetic effects might explain the differences. Perhaps we should begin inbreeding strains of zebra finches to facilitate genetic studies in the future. Also, we may need to investigate other lab bred species of songbirds used by researchers such as Bengalese Finches, which have been bred in captivity for centuries and selectively bred for their plumage.

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[1] (Parrots and hummingbirds are also vocal learners.)

[2] This process of sibling-sibling breeding is also known as “selfing.” The Ancient Egyptians, believing the royal family to be gods bred brothers and sisters for 10 generations, and likely created humans homozygous at each allele.

[3] Of course, due to the sex chromosomes, males and females will have different genomes, and a small number of new mutations occur with each generation.

[4] Though they are far from perfect: http://en.wikipedia.org/wiki/Microsatellite#Limitations. Although mutations can complicate analyses, previous studies by Forstmeier et al. demonstrated that they are extremely rare in Zebra finches — they did not observe a single event in their microsatelli loci in 7368 parent offspring comparisons.

References:

Forstmeier W, Segelbacher G, Mueller JC, Kempenaers B. Genetic variation and differentiation in captive and wild zebra finches (Taeniopygia guttata). Mol Ecol. 2007 Oct;16(19):4039-50.


Alzheimer’s disease (AD) is by far the number one cause of dementia, and the number one risk factor for AD is age–with almost 50% of people above the age of 85 suffering from the disease.

Common Dementia SyndromesAlzheimer Disease Prevalence and Projected Population

With the aging baby boomer generation and medical advances squaring off the life expectancy curve, the United States is projected to have over 9 million cases of AD by 2050. This huge expected increase in cases has been dubbed by some as the “Alzheimer’s Disease Epidemic.”

Alzheimer’s disease is marked primarily by memory loss and inability to form new memories, but it can also impair language, higher thinking, visuospatial skills, and can even cause personality changes and delusions. By erasing patients’ identities, memories, and personalities, Alzheimer’s disease robs patients of their humanity, and can be devastating for the friends and family watching the disease unfold.

Auguste D - First Patient with Alzheimer'sAuguste D.’s story

Alzheimer’s disease was first described in 1901, a patient Auguste D., a 51-year-old woman, suffering from debilitating memory loss, deficits, and precatory delusions. She underwent a progressive decline and died five years later. The case was described by Alois Alzheimer a German psychiatrist and neuropathologist (though now the disease is treated by neurologists).

The fact that Alzheimer was a pathologist was of crucial importance. Because of it, he performed an autopsy on Auguste D. and discovered proteinaceous plaques, and neurofibrillary tangles in the woman’s brain, which to this day remain the pathological hallmarks of Alzheimer’s disease:Alzheimer's Disease Brain - Senile Plaques Neurofibrillary Tangles - Pathalogical Hallmarks

Alzheimer’s mentor, Kraepelin, was the first to use the eponym “Alzheimer’s Disease” in 1904, and his writing about the disease was prescient:“Although the anatomical findings suggest that we are dealing with a particularly serious form of senile dementia… this disease sometimes starts as early as in the late forties.”

This clinical observation was borne out by later genetics. There is an early onset familial variant of the AD, that is caused by rare mutations. Familial AD is devastating, otherwise normal, healthy patients in their 40s or younger, but luckily it accounts for a minority of cases. The later-onset variant has complex genetic and environmental risk factors and accounts for the vast majority of cases. In this variant genetic factors such as the ApoE4 allele are known to increase the risk of Alzheimer’s, but a doctor cannot genetically predict who will get it and who won’t.

Genetics of Alzheimer's Disease - Familial Early Onset and Sporadic Late Onset

What was really interesting about the first three genes identified in familial Alzheimer’s disease is that they are part of the same pathway. These genes code for the amyloid precursor protein (APP), and presenilin 1 and 2. Amyloid precursor protein is cleaved by the “gamma secretase complex,” an enzyme that is made up of multiple subunits, including presinilin 1 & 2. If APP is cleaved at the wrong locations, it forms a protein fragment beta-amyloid, which can induce other proteins to misfold, forming a protein aggregate that grows like a snowball rolling down a hill. This protein aggregate eventually forms a giant extracellular plaque—the very same plaques that Alzheimer’s described in his patient Auguste D!

APP Beta-Amyloid Schematic Enzymes Cleavage Presinillin 1 & 2 APP Beta-Amyloid Schematic Plaque Formation Aggregate

The Amyloid Cascade Hypothesis

This genetic work led to the amyloid cascade hypothesis: that extracellular amyloid accumulates and initiates a sequence of events, eventually leading to neurotoxicity and clinical symptoms in AD. This hypothesis has inspired a number of clinical trials to test drugs to treat or slow the course of Alzheimer’s, by attempting to stop the formation or remove these beta-amyloid plaques. Even when trials have been successful y removed patient’s plaques, patients have not shown clinical improvements. It is unclear whether the amyloid cascade hypothesis is wrong (and perhaps amyloid plaques correlate with but do not cause AD), or whether we are just starting our treatments too late once the cascade of neurodegeneration is initiated–but that these treatments could be successful if we used them on patients earlier in their disease course.

In fact we know that patients with Alzheimer’s disease don’t show clinical symptoms until late in the disease, perhaps due to a phenomenon known as cognitive reserve. New techniques however, allow us to determine whether people showing subtle cognitive deficits are at high or low risk of developing Alzhiemer’s, and therefore we can continue to test the amyloid cascade hypothesis by perforing clinical trials using the drugs we know clear plaques on people who are of high risk of developing Alzheimer’s.

For example, the same proteins found in the plaques and tangles in Alzheimer’s disease brains such as amyloid beta make their way into the cerebrospinal fluid which coats the brain and spinal cord. In patients with mild cognitive impairment–meaning they are starting to show cognitive problems compared to age-matched, education-matched controls, but not severe enough to be classified as Alzheimer’s–we can perform lumbar punctures to harvest their cerebrospinal fluid. Then by measuring levels of these proteins found in plaques, we can predict which of these patients with MCI are at high risk of progressing to Alzheimer’s.

Progession to AD Normal CSF Pathological CSF Hansson et alHansson et al., Lancet Neurol (2006)

Additionally, we can look at the burden and distribution of plaques in the brain using radioactive PET ligands that bind to the plaques:

awn320 1310..1323

And we are developing techniques to non-invasively visualize and quantify the burden of this plaques in retina: Amyloid Plaques in Retina

The Cholinergic Hypothesis

While the previously-described techniques will inevitably assist with the diagnosing AD, the amyloid cascade hypothesis is still unproven, and so far has not lead to any effective therapy. Currently, one of the best treatments for Alzheimer’s disease is lifestyle modification: labeling and arranging one’s life as memory declines. The mainstay of pharmacological approach for AD are cholinesterase inhibitors developed in the 1990s and 2000s, which can improve performance on cognitive tests.

Acetycholinesterase mechanism Ach

These drugs block acetylcholinesterase, blocking the breakdown of the neurotransmitter acetylcholine into acetate and choline, so the drugs therefore they increase levels of acetylcholine in the synapse and signaling to the postsynaptic cell.

You might be wondering, how do these drugs help treat Alzheimer’s if it is a disease caused by plaques, tangles and neurodegeneration? Why did we develop and test them in the first place?

These drugs were actually developed based on an earlier theory of Alzheimer’s the cholinergic hypothesis.

In the 1960s and ‘70s psychologists gave young healthy subjects cholinergic inhibitors (which prevent acetylcholine from signaling to post-synaptic cells). These young healthy subjects had memory problems and cognitive problems that resembled patients with Alzheimer’s disease, showing that acetylcholine was important for memory.

Cholinergic projections in brain basal forebrain nucleus of Meynert

Most of the brain’s supply of acetylcholine derives from the nucleus basalis of Meynert in the basal forebrain, so doctors investigated this area during the autopsies of patients with Alzheimer’s and showed that the nucleus basalis seems to be particularly vulnerable to the neurodegeneration seen in AD. Patients showed decreased numbers of healthy neurons in this area, and decreased cholinergic projections to the hippocampus and entorhinal cortex (areas we also knew were important for memory), suggesting that patients with AD may have decreased acetylcholine.

Going back to the drugs we use for Alzheimer’s cholinesterase inhibitors, these drugs are thought to boost the remaining acetylcholine signaling going on in synapses, similar to how SSRIs increase the amount of serotonin. However, because they are not preventing the neurodegeneration that is causing AD, disease progression continues and causes massive neurodegeneration, eventually killing patients by interfering with their ability to swallow and breath.

Hypothesized Treatment effect of cholinesterase inhibitors in AD

However, if the cholinergic hypothesis is correct, and disruptions to the acetylcholine signaling from the basal forebrain is especially important for the symptoms of AD, then maybe if we can selectively prevent degeneration of this area we can slow the disease. Currently clinical trials are delivering of Nerve Growth Factor (NGF) to the basal forebrain using gene therapy approaches—implanting stem cells that produce NGF or using viruses to modify cells in the basal forebrain to produce it themselves. Nerve Growth factor is known to increase the growth and vitality of cholinergic neurons, and may therefore help preserve the cells as they suffer early insults of Alzheimer’s.

Even if Nerve Growth Factor gene therapy can just slow the disease, we can give patients more time with their memories intact to enjoy their families and a dignified independent life. We can decrease the time families and friends spend caring for a person who’s face the recognize, but whose mind becomes increasingly unfamiliar, and we can decrease the time patients have to spend institutionalized or with a full time caretaker.

Clinical research is slow, and research is never certain, but the new approaches to Alzheimer’s give hope to a Alzheimer’s disease—a disease where prognoses for patients like Auguste D. have remained gloomy for over a century, and where an epidemic of new cases looms ahead in the near future.


Medieval medicine practices were... "interesting."

“This urine wheel was published in 1506 by Ullrich Pinder, in his book Epiphanie Medicorum. It describes the possible colours, smells and tastes of urine, and uses them to diagnose disease.”
Jeremy K. Nicholson & John C. Lindon Nature 2008 (1)

Metabolomics has come a long way since the days of tasting urine. Now techniques like high-throughput mass spectrometry can provide us detailed information about the small molecules we find in the body–which can be influenced by diet, environmental exposure (to toxins, medicine, etc), or even the gut microbiome. Metabolomics will also capture the genetic or epigenetic differences in  how individuals process these exposures.

Metabolome-Wide Association Studies

New high-throughput technologies have great potentials is unbiased case-control studies looking at as many metabolites as possible–Metabolome Wide Association Studies (similar to the GWAS studies done in genetics). These studies would look for the association of any metabolite with a given disease–after which research into that metabolite could indicate a variety of causes–nutritional differences, environmental exposure, or even mutations in metabolic pathways.

Any given study would not be the end all, as metabolomic exposure occurs over a life-time. Other important factors may include exposures while in the womb to teratogens–substances that interfere with the development of an embryo or fetus that cause birth defects.

The most famous example of a teratogen is probably the drug Thalidomide that interfered with limb bud development.

Metabolomics and Neursocience

Metabolomics research is in it’s infancy and it hasn’t yet been applied to psychiatric or neurological disease. The GWAS for psychiatric disease were not as fruitful as was originally hoped–probably due to both the complex natures of the diseases and also the murkiness of symptom-based disease classification of psychiatric disease. The same classification problems would make MWAS of psychiatric disease, but it would be one step to help explain environmental factors (e.g. why one genetically identical twin gets schizophrenia while another doesn’t).

MWAS techniques could also be used identify biomarkers which can be used in either the identification of psychiatric disease, or subcategorization of a disease. A good biomarker would make studies more reproducible, or alternatively multiple markers could and help seperate similarly-manifesting diseases.

We really have a wealth of riches in terms of high-data yielding approaches to tackle these diseases: genomics, epigenomics, metabolomics, and brain-imaging. Unfortunately these methods remain expensive, time consuming. Currently one of the biggest hold-ups in metabolomics is man-power on the bioinformatics side of interpretting the mass/spec results. Further, we haven’t figured out all the best ways to analyze and make sense of all this “Big Data” biology. Personally, I think it will be extremely powerful in situations where the results can be quickly verified using traditional reductionist experimental approaches. If machine learning keeps it up, maybe the data will even analyze itself.

All in all, I am very interested to see where this goes. There are hundreds of thousands of metabolites in what we eat alone and so far we are only scratching the surface.

References

1. Nicholson, J. K. and J. C. Lindon (2008). “Systems biology: Metabonomics.” Nature 455(7216): 1054-1056. http://dx.doi.org/10.1038/4551054a

2. Jones, D. P., Y. Park, et al. “Nutritional Metabolomics: Progress in Addressing Complexity in Diet and Health.” Annual Review of Nutrition 32(1): 183-202. http://www.annualreviews.org/doi/full/10.1146/annurev-nutr-072610-145159


Here are the articles I thought were tweet-worthy in July 2012. If you find the topics interesting, follow me on twitter. I really appreciate your support.

July was an interesting month, including: unconscious passwords stored in procedural memory, neuroethics of the “gay gene,” Virtually THC-free (but CBD-rich) marijuana, oh and lets not forget the Higgs Boson (puts things in historical context).

The Feed:

25 JulNeuroamer Blog ‏@Neuroamer

Brain: The precuneus: review – involved in self-consciousness, engaged in self-related mental representations – http://bit.ly/LO2lnZ 

25 JulNeuroamer Blog ‏@Neuroamer

http://scienceblog.com/55711/children-in-foster-care-develop-resilience-through-compassion/ … children in foster care develop resilience through compassion meditation

25 JulNeuroamer Blog ‏@Neuroamer

List of movies with psychological or cognitive science themes – Indiana http://bit.ly/PIANW8 

25 JulNeuroamer Blog ‏@Neuroamer

A Single Brain Structure May Give Winners That Extra Physical Edge: Scientific American – t http://bit.ly/LNKb5Q 

24 JulNeuroamer Blog ‏@Neuroamer

The American Scholar: Living With Voices – T. M. Luhrmannhttp://bit.ly/PBJ1iN  – Thought-provoking alternative view on auditory hallucinations
Continue reading ‘Month in Review: July – Unconscious passwords, “gay genes,” high-less pot, and the Higgs Boson’


Cytosine, 5-mC, 5-hmC

5-hydroxy-methyl CpGs (5-hmCs) were first discovered in 2009 and shown to be enriched in the brain, but remain a mysterious epigenetic mark, despite intriguing functional findings such as: environmental enrichment’s reduction of it, MeCP2’s preference for 5mc over 5hmc, and it’s possible role as an intermediate in demethylation. This new technique will aid their characterization by allowing absolute quantification and base-resolution localization of the marks. The technique also serves as a reminder of why you should pay attention in orgo, or at least why you should collaborate with people who did!

Now, Emory’s Peng Jin, has collaborated with University of Chicago chemist He Chuan to develop a new derivative of bisulfite sequencing, Tet-Assisted Bisulfite Sequencing (TAB-Seq) that distinguishes 5-hmcs from 5-mcs, as they describe in cell.

methylC-Seq is so passe these days

Yu (2012) Cell

Traditional bisulfite sequencing (MethylC-Seq):

  1. Sequence the sample
  2. Treat the sample with bisulfite, which converts all non-methylated cytosines to uracils, but leaves 5-mCs and 5-hmCs as cytosines. (The even rarer base 5-carboxy-C (5-caC), is converted by bisulfite into 5-caU.)
  3. Resequence.
  4. Compare your first sequence to your second. You know the unmethylated cytosines from the first sequence will show up as Ts in the second sequence (because when they are amplified, they will be amplified as Thymidine not Uracil). The methylated and hydroxy-methylated cytosines which show up as Cytosines in both sequences.

TAB-seq

So, how can we differentiate 5-hmCs from 5-mCs? In a process that may remind you of all those organic chemistry synthesis problems, TAB-seq involves an extra step to protect the hydroxy-methylated cytosines from TET oxidation.

  1. Glucosylate 5hmC using β-glucosyltransferase (βGT).
  2. 5mC is oxidized to 5caC by with an excess of recombinant Tet1. (The blocked 5hmCs (β-glucosyl-5-hydroxymethylcytosine (5gmC) ) are not oxidized.)
  3. Treat the sample with bisulfite. This converts the Cs and 5-caCs to Us, but doesn’t effect the 5gmC.
  4. Resequence
  5. Compare back with traditional bisulfite sequencing. The 5-hmCs are the bases that show up as Cs in these two sequences. (5-mCs will show up as Ts in TAB-seq, but Cs in traditional. Unmodified Cs and CaCs will show up as Ts in both sequences.)

Validation and Findings

Validation of new techniques (proof that they work), is always important, and the paper shows that it works using mass spectrometry.

They validated it’s practicality, by using the technique to map 5-hmCs in human embryonic stem cells (hESCs) and mouse embryonic stem cells (mESCs). In hESCs they found 691,414 5hmCs with a false discovery rate of 5%. Interestingly, though mice have similarly sized genomes, they found much higher levels of 5hmCs–2,057,636–which they hypothesize is also due to the higher levels of Tet1 and Tet2 proteins.

So where are 5hmCs enriched, now that we can identify them precisely? H1 distal-regulatory elements including p300-binding sites (observed/expected [o/e] = 7.6), predicted enhancers (o/e = 7.8), CTCF-binding sites (o/e = 5.1)–CTCF is a transcriptional repressor that blocks interactions between promoters and enhancers and also plays a role in stopping the spread of heterochromatin, and DNase I hypersensitive sites (o/e = 3.4) which are associated with active gene expression. Because, 5-hmCs are enriched at enhancers, the authors speculate that 5-hmC may be  specifically recognized by transcription factors as a core base in binding motifs.

Not so sure about this X-mas coloring scheme

Genomic Distribution of 5hmC Sites. Yu (2012) Cell.

Many genes had significant enrichment of 5hmC, but lowly expressed genes had more than highly expressed. 5hmCs  showed asymmetry, with more hydroxylation on strands where the CpG was surrounded by Gs. (A similar pattern wasn’t observed for 5mCs.)

5hmCs also tended to be enriched near low CpG areas

Previous findings that identified 5hmCs in high CpG areas, such as CpG island-containing promoters, but these findings are likely do to the bias of mapping techniques which can amplify frequent weak signals and overshadow sparse but strong ones.  The present study, found that 5hmCs tended to be enriched in lower CpG areas, especially those with H3K4me3 or bivalent (H3K4Me3 and H3K27ac) chromatin modifications, but how 5hmC interacts with the histone code is still up in the air.

Conclusion

It will be interesting to see if the findings from, generalize to different cell-types, but since hESCs and mESCs showed similar patterns, it suggests that the regulation at least in stem cells is evolutionarily conserved.

It seems this tree will have bountiful fruit, weighing down the branches for some time. I’ll leave a final summary in the authors’ own words:

“We have developed a genome-wide approach to determine 5hmC distribution at base resolution and have generated base-resolution maps of 5hmC in both hESCs and mESCs. These maps provide a template for further understanding the biological roles of 5hmC in stem cells as well as gene regulation in general. In conjunction with methylC-Seq, the TAB-Seq method described here represents a general approach to measure the absolute abundance of 5mC and 5hmC at specific sites or genome-wide, which could be widely applied to various cell types and tissues.”

References
Kriaucionis, S., & Heintz, N. (2009). The nuclear DNA base , 5-hydroxymethylcytosine is present in brain and enriched in Purkinje neuronsScience,  324(5929), 929-930. (Free full text.)

Szulwach, K. E., Li, X., Li, Y., Song, C.-X., Wu, H., Dai, Q., Irier, H., et al. (2011). 5-hmC-mediated epigenetic dynamics during postnatal neurodevelopment and aging. Nature neuroscience, 14(12), 1607-16. Nature Publishing Group. doi:10.1038/nn.2959

Yu M, Hon GC, Szulwach KE, Song CX, Zhang L, Kim A, Li X, Dai Q, Shen Y, Park B, Min JH, Jin P, Ren B, & He C (2012). Base-resolution analysis of 5-hydroxymethylcytosine in the Mammalian genome. Cell, 149 (6), 1368-80 PMID: 22608086

Guo, J. U., Su, Y., Zhong, C., Ming, G.-li, & Song, H. (2011). Emerging roles of TET proteins and 5-hydroxymethylcytosines in active DNA demethylation and beyond. Cell Cycle, 10(16), 2662-2668. doi:10.4161/cc.10.16.17093

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You may also be interested in the brief article I wrote previously about 5-hmCs and a paper that showed that they are highly enriched in the cerebellum and hippocampus (10x higher than in stem cells), and they increase with age. Further, the authors showed that MeCP2–which strongly binds the unhydroxylated and more ubiquitously expressed version, 5-methyl CpGs–does not bind 5-hmCs. Overexpression of MeCP2 even seems to block TETs from converting 5-mCs into 5-hmCs.

Update:

Just learned about oxBS-Seq another method for sequencing, need to look into this. Does anyone know off-hand advantages/disadvantages of either?

http://epigenie.com/oxbs-seq-breaks-through-5hmc-sequencing-barrier/

http://www.sciencemag.org/content/336/6083/934.abstract

http://www.sciencemag.org/content/336/6083/934.abstract

ResearchBlogging.org


MARS PROJECT

You may have seen my tweet about the upcoming documentary Mars Project, which tackles complex issues such as mental illness, drug use, psychiatry, race, and stigma. When director Jonathan Balazs contacted me about his film, I got really excited about it.

Khari “Conspiracy” Stewart, rapper in the Canadian indie hip hop group Supreme Being Unit

If you liked the teaser but want to learn more about the project, check out Balazs’s Indie-Go-Go page (the film is still in production and could really use your help). You might also be interested in the original short film, and my interview with Balazs below.

It’s great topic for Balazs to have chosen, and extremely courageous of “Conspiracy” to discuss and publicize his diagnosis of schizophrenia–a heterogenous disorder that is often swept under the rug, despite the fact that ~1% of the human population suffers from it’s symptoms. There is are a lot of misconceptions surrounding schizophrenia, and I think Mars Project will reach a lot of people that might otherwise be misinformed about the disorder. Further, with a neurotypical identical twin, I think “Conspiracy” is an especially great example of the complexity of psychiatric disease–although schizophrenia has a genetic component, it is far less heritable than autism, and GWAS studies have failed to turn up likely candidate genes.

Despite the difficulty of the problem, I think that genetics will give us the insights to explain schizophrenia biologically within my lifetime. But it will be important for psychiatrists and neuroscientists to remember the other side of biological reductionism–our experiences and thoughts are constantly affected the biochemistry of our brain. We need to explore the whole bio-psycho-social environment for therapies in addition to looking for cleaner drugs.

portrait of filmmaker

Jonathan Balazs

What inspired you to make a film where schizophrenia and mental illness plays such a central role?I felt like this whole process was an exercise in self-discovery. The whole process was cumulative, one that developed quite opposite of an Archimedean moment. I had some academic influences sure, but my education came from an innate sense of curiosity toward this mysterious and sometimes terrifying mental disorder called Schizophrenia. As I tried to pin down what it meant to me or how to make sense of it, the more elusive a definition came. I’m probably more confused by that label now than I was when I first began my inquiry.

In doing research for the film, did you find any good resources explaining schizophrenia, mental illness, etc.?

Yes and no. Symptoms of Schizophrenia (and pretty much any mental disorder) are not so cut-and-dried like a knee-scrape or heart condition, as these are easily observable medical phenomenon. Schizophrenia on the other hand seems more like a philosophical concept, rather than a medical one – a split between a shared universally accepted human reality (if there is such a thing) and someone who’s simply too involved in their own mind. The dimensions of human expression are too complex, unpredictable and culturally influenced that there can be no concrete definition as they currently stand. I was quite surprised to discover a growing number of psychiatrist doctors who agreed with this and who defined people by their identity vs. their brain organ.
My research into these issues is ongoing, but I have found a great deal of value in the work of Dr. R.D. Laing (someone I wish I could have shared a drink with) and Dr. Thomas Szasz. I think it’s unfortunate that they have been labeled as patriarchs of the “Anti-Psychiatry” movement because there is value in what they have written. One of our interview subjects Dr. Gordon Warme has been a defining influence in my study of mental illness and on Mars Project. I’ve been trudging through Michel Foucault’s writings and wonder where the popular philosophers are in 2012 – it seems like they’ve been replaced by the theoretical physicists and astronomers.

What was it like to meet “Conspiracy” for the first time?

Loud, I think we were at a rap show.

How did you find the psychiatrists you interviewed for the film? Was it difficult finding academics willing to go on camera?

I have to give credit where it’s due; executive producer David Reville was instrumental in those interviews as I’m still very “green” with respect to disabilities studies and psychiatry. He was the one who put together the interviews with Dr. Gordon Warme, Dr. Kwame McKenzie and disabilities scholar Erick Fabris. We were very fortunate to receive insight from these people all doing important work in their area(s). I think the most difficult aspect of interviewing them was scheduling them all on the same day. I don’t think it could have been more successful honestly.

Do you think mental illness can be explained entirely through biology? Are you, yourself, a spiritual person?

Those are two different questions, I think. No, I don’t think the biological argument is entirely sufficient to explain these mental illness phenomena. I don’t think I’m qualified to say that there could never be a biological explanation, though I will note that ‘biology’ seems to be a primer for something that can’t be explained fully. I have too much respect for human culture to chalk up society as a vast network of neurons farting out serotonin and dopamine. For some people the medical model might ring true; those who do follow the path of the shaman in the white lab-coat are free to do so because the path of “recovery” (or more aptly management) lies within the individual.

I am not a spiritual person by most definitions and definitely not religious, I sometimes refer to myself as a rational agnostic.

What role do artists play in spreading scientific information?

I think it’s important that more artists recognize and value the influence of scientific discourse, though I admit that there is a concern with this information being presented accurately (and to an extent objectively) while still keeping with the identity of the artist. I would add that art and science are far too often pitted against each other when they’re essentially cut from the same cloth. It encouraged me to hear Dr. Kwame McKenzie discuss the art of psychiatric medicine in our interview.

After getting to know “Conspiracy” so well, are there parts of the psychiatric system or the way we address these illness,that you personally think need to be changed?

I can only say what I might do for myself, because fixing the mind lies with the patient alone – psychiatry is just one of the tools available. If I ever suffer from prolonged psychosis, who knows what I’d do? My feeling though, is that many of these potent, mind-altering psychiatric drugs are prescribed too freely – as if the answer to your crisis can be sought through a little pill. Some of these drugs essentially dull every aspect of your spirit and not just those undesirable or offensive aspects of behavior. The systematic, state-imposed ‘zombification’ of vulnerable individuals doesn’t seem like the best path; some might read this and ask what business a filmmaker has on mental health policies.

When will the movie be released, and do you have other upcoming projects?

The film will be completed by the fall and hopefully it will hit festival screens in the autumn. I hope that we’ll be able to negotiate wide distribution in theatres and certain online and V.O.D. platforms. With the amount of cussing in the film, I doubt that many networks will want to program it on their channels.

I’m working on a short documentary featuring the work of illustrator Pearl Rachinsky and I’m hoping to shop around an expanded treatment based on a short film I wrote a few years ago called Thane Spa on the monetization of suicide.

For more information on Mars Project see www.marsprojectmovie.com, ‘like’ us on Facebook, check our Youtube channel and please help us support our indiegogo campaign. I’m a little too serious on Twitter, but you can follow me just the same @BrandoBalazs.

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Know of any good movies or documentaries out there about mental illness or schizophrenia? I need to watch something while I wait for Mars Project, so suggestions would be great!


What prescription drugs do we take and why are we taking them? Get a glass of water, choke down your horse pills, and take a look at the 10 most prescribed psychiatric drugs, 10 most prescribed drugs overall, and the 10 most profitable drugs, followed by a bit of analysis (though maybe what you need is psychoanalysis).
Top 10 most prescribed drugs psychiatric drugs the United States (according to IMS Institute for Healthcare Informatics in 2009)
Thats a lot of scripts
Rank Brand Name Generic Name # of U.S. Prescriptions Use
10 Valium Diazepam 14,009,000 Anxiety, Panic disorder
Benzodiazapene – Positive allosteric modulation of GabaA Receptors – (Facilitates GabaA inhibition in use dependent manner)  Beautiful, beautiful resonance
9 Effexor XR Venlafaxine 14,992,000 Depression,Anxiety, Panic disorder – “Off-label” for diabetic neuropathy and migrane
Serotonin-norepinephrine reuptake inhibitor (SNRI) – increases serotonine and norepinephrine How did they come up with names like venlafaxine?
8 Seroquel Quetiapine 15,814,000 Schizophrenia, Bipolar disorder, “add-on” for Depression
“Atypical antipsychotic” – Blocks dopamine, serotonin, adrenergic and histamine receptors What ever happened to good old fashioned dopamine blockers...
7 Cymbalta Duloxetine 16,626,000 Depression,Anxiety, fibromyalgia, diabetic neuropathy
Serotonin-norepinephrine reuptake inhibitor (SNRI) – increases serotonine and norepinephrine in a use dependent manner Another SNRI on the list
6 Desyrel Trazodone 18,873,000 Depression, Bipolar Depression (sometimes), Anxiety
Predominantly a 5-HT2A receptor antagonist, also 5-HT1A partial agonist and Selective Serotonin Reuptake inhibitor (SSRI) Anti-depressant and anti-psychedelic
5 Prozac Fluoxetine 19,499,000 Depression, Anxiety, OCD, Bulemia, PMDD
Selective Serotonin Reuptake inhibitor (SSRI), 5-HT2C receptor antagonist, σ1 Receptor agonist Love that squiggly "enantiomer" line
4 Zoloft Sertraline 19,500,000 Depression,Anxiety, OCD,PTSD, PMDD
Selective Serotonin Reuptake inhibitor (SSRI) – Weak σ1 receptor agonist and α1-adrenoreceptor antagonist Zo-loft
3 Ativan Lorazepam 25,868,000 Anxiety, panic disorder
Benzodiazapene – Positive allosteric modulation of GabaA Receptors – (Facilitates GabaA inhibition in use dependent manner) Remember, the -Pams are -Pines, or in the 60s: Bennies.
2 Lexapro Escitalopram 27,698,000 Depression,Anxiety
Selective Serotonin Reuptake inhibitor (SSRI) Escape your troubles with Escitalopram
1 Xanax Alprazolam 44,029,000 Anxiety
Benzodiazapene – Positive allosteric modulation of GabaA Receptors – (Facilitates GabaA inhibition in use dependent manner) And our winner, the number one most prescribed drug in the USofA

Mmmm... 3D pie.

It’s a little crazy, pun totally intended, how much we’re prescribing SSRIs, when some meta analyses say they aren’t much better than placebo. Placebo effects are probably doing something very physiological in this case, by relieving anxiety. I would say that sugar pills would be a lot cheaper and save us money, but I don’t think we need more sugar either. Maybe, we should go Germany’s route and prescribe St. John’s Wort for mild depression?

Top 10 most prescribed drugs in the United States overall (according to IMS Institute for Healthcare Informatics in 2011)
  • 10. Hydrochlorothiazide (various brand names) lowers blood pressure — 47.8 million
  • 9. Generic Glucophage (metformin) diabetes drug — 48.3 million
  • 8. Amoxicillin (various brand names) antibiotic — 52.3 million
  • 7. Azithromycin (brand names include Z-Pak and Zithromax), antibiotic — 52.6 million
  • 6. Generic Prilosec (omeprazole), antacid drug — 53.4 million (does not include over-the-counter sales)
  • 5. Generic Norvasc (amlodipine besylate), angina/blood pressure drug — 57.2 million
  • 4. Generic Synthroid (levothyroxine sodium), synthetic thyroid hormone — 70.5 million
  • 3. Lisinopril (brand names include Prinivil and Zestril), blood pressure drug — 87.4 million
  • 2. Generic Zocor (simvastatin), cholesterol-lowering statin drug — 94.1 million
  • 1. Hydrocodone (combined with acetaminophen), opiate/painkiller — 131.2 million

This list doesn’t contain any psychiatric drugs–Xanax just barely misses the cut–but the #1 drug, hydrocodone, is psychoactive. However, while our #1 psychiatric drug did not make it into the top 10 most prescribed, our #8 drug, the atypical antipsychotic Seroquel clocks in at #6 on the drugs we spend the most money on (shown bellow).

Also of note, is the #1 most prescribed drug for teenagers. Can you guess what it is? Methylphenidate, Ritalin, the ADHD medicine. I’m most surprised it’s not adderall at this point.

According to ABC news: “The United States makes up only 4.6 percent of the world’s population, but consumes 80 percent of its opioids — and 99 percent of the world’s hydrocodone, the opiate that is in Vicodin.” Our use of hydrocodone and other opiate painkillers has many issues: such as diversion and abuse and use as a bandage in chronic pain or injury instead of treating underlying issues (where it may even make pain worse in the long term). Another startling new trend, is the spike in newborns born dependent on opiates:

The best sellers are often generic drugs, so it is also interesting to see where “big pharma” is making the most money:

Top 10 drug we spend the most money on in the United States overall (according to IMS Institute for Healthcare Informatics in 2011)

  • 10. Epogen, injectable anemia drug — $3.3 billion
  • 9. Actos, diabetes drug — $3.5 billion
  • 8. Crestor, cholesterol-lowering statin drug — $3.8 billion
  • 7. Singulair, oral asthma drug — $4.1 billion
  • 6. Seroquel, antipsychotic drug — $4.4 billion
  • 5. Abilify, antipsychotic drug — $4.6 billion
  • 4. Advair Diskus, asthma inhaler — $4.7 billion
  • 3. Plavix, blood thinner — $6.1 billion
  • 2. Nexium, antacid drug — $6.3 billion
  • 1. Lipitor, cholesterol-lowering statin drug — $7.2 billion

Note the atypical antipsychotics Seroquel and Abilities. One meta-analysis of antipsychotics, showed they have questionable benefit over the now-generic typical antipsychotics, and were not a cost-effective answer. The studies analyzed all suffer from the same difficulties that genetics studies of schizophrenia do, because patients are so heterogeneous and diagnoses are somewhat subjective. Atypical prescriptions are probably too high, due to advertising and “newer is better” kind of thinking, but because the disorders are heterogeneous, I’m glad that we have more drugs to choose from and try out with individual patients.

Also, I’m also shocked that antacid drugs can make that much money, but I guess it’s in a different ballpark than Tums.

References / Further Reading
Turner, E. H., Matthews, A. M., Linardatos, E., Tell, R. A., & Rosenthal, R. (2008). Selective Publication of Antidepressant Trials and Its Influence on Apparent Efficacy. New England Journal of Medicine, 358(3), 252-260. Massachusetts Medical Society. doi:10.1056/NEJMsa065779

Hanrahan, P., Luchins, D. J., Fabian, R., & Tolley, G. (2006). Cost-effectiveness of atypical antipsychotic medications versus conventional medication. Expert Opinion on Pharmacotherapy, 7(13), 1749-1758. Expert Opinion. doi:10.1517/14656566.7.13.1749




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