The 'Homer Simpson gene' found

No kidding. A gene that makes mice dumber than they can potentially be and which also exists in humans (mice are very close relatives of us). Naturally the researchers have nicknamed it the "Homer Simpson gene".

The gene is techically known as RGS14 and is part of the CA2 region. Mice with the RGS14 gene knocked down (marvels of genetic engineering) surprisingly were much faster and effective than their normal cousins navigating mazes and overcoming obstacles. In other words: they were mice geniuses of sorts.

Naturally this finding begs a question:

why would we, or mice, have a gene that makes us less smart -- a Homer Simpson gene?

Good question. Scientists still do not know. I wonder if they should knock out that gene in themselves before the next research. Ok, sure, now I am kidding... or maybe not.

Why do we have a gene that makes us, it seems, dumber than we could potentially be. What advantages does stupidity confer?

Or does its absence cause some other kind of problems? Researchers speculate on some possible related issues (epileptic seizures, altered social behavior) but so far have not been able to find any clear correlation: the Homer Simpson gene makes you dumb and its absence does not seem to confer any disadvantage whatsoever.

So what's going on? Why hasn't this gene be selected against? Nobody knows... yet.

Source: Science Daily.

Ref. Sarah Emerson Lee et al., RGS14 is a natural suppressor of both synaptic plasticity in CA2 neurons and hippocampal-based learning and memory. PNAS 2010. Pay per view depending on where and when.

Breastfeeding greatly increases IQ

New research confirms that breastfeeding (by contrast to formula feeding) increases the IQ of children even in the challenged case of a particular minority polymorphism, which, according to this new paper, is actually the diplotype that shows greater and not lowest influence of breastfeeding on IQ.

Colin D. Steer et al, FADS2 Polymorphisms Modify the Effect of Breastfeeding on Child IQ. PLoS ONE 2010. Open access.

Background

Breastfeeding is important for child cognitive development. A study by Caspi et al has suggested that rs174575 within the FADS2 gene moderates this effect so that children homozygous in the minor allele (GG genotype) have similar IQs irrespective of feeding method.

Methods and Principal Findings

In our study of 5934 children aged 8 years, no genetic main effect with IQ was found for rs174575. However, an interaction with this polymorphism was observed such that breastfed GG children performed better than their formula fed counterparts by an additional 5.8 points [1.4, 10.1] (interaction p = 0.0091). Interaction results were attenuated by about 10% after adjustment for 7 factors. This study also investigated rs1535, another FADS2 polymorphism in linkage disequilibrium with rs174575, together with performance and verbal IQ, finding similar results although effect sizes were generally reduced.

Conclusions and Significance

This study did not replicate the findings of Caspi et al. In contrast to their study, GG children exhibited the greatest difference between feeding methods such that breastfed children performed similarly irrespective of child genotype whereas formula fed GG children performed worse than other children on formula milk. Further studies are required to replicate these findings.

Figure 1. Unadjusted means for Full-scale IQ at 8 years for breastfeeding (yes/no) and child FADS2 genotypes with 95% CIs (N = 5045 (A) and 5099 (B)).

Genes for bad driving, genes for drinking, genes for all...

Not sure how solid are these news items but today Science Daily publishes two articles on how genes make you this or that.

One quite common genetic variant (30% in USA) makes you apparently a worse driver, and a worse learner in general. However it is very advantageous to overcome neurodegenerative diseases. It is probably one of these cases of dynamic equilibrium in which two alleles offer different adaptative advantages, each one at a different cost.

Another of these allele variants has been found to increase the like for alcohol and make people drink more, however it is independent on the gene that predisposes to alcoholism (alcohol-addiction). This does not change that drinking frequently is the leading cause of alcoholism, of course, just mentions genes that predispose to drinking and to alcohol-dependence as distinct.

I just wonder what adaptative advantage does the gene for alcoholism has, sincerely. There must be something or would have gone extinct.
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Spanking children makes them dumb

That is the conclusion of a study (paywall) by US researchers: that regular spanking is extremely altering and causes traumatic post-stress disorder reducing the young brain's ability to cope and develop normally.

The good news is that, as the practice of corporal punishment is steadily decreasing worldwide, the intelligence of the new generations is improving overall. In fact, it may be an important factor in the Flynn effect.

Source: Science Daily.
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Genes and music

A new and surely interesting paper on one of the less studied aspects of intelligence: musical abilities and its relation with specific genes:

L.T. Ukkola et al.,Musical Aptitude Is Associated with AVPR1A-Haplotypes. PLoS ONE, 2009.

Abstract:

Artistic creativity forms the basis of music culture and music industry. Composing, improvising and arranging music are complex creative functions of the human brain, which biological value remains unknown. We hypothesized that practicing music is social communication that needs musical aptitude and even creativity in music. In order to understand the neurobiological basis of music in human evolution and communication we analyzed polymorphisms of the arginine vasopressin receptor 1A (AVPR1A), serotonin transporter (SLC6A4), catecol-O-methyltranferase (COMT), dopamin receptor D2 (DRD2) and tyrosine hydroxylase 1 (TPH1), genes associated with social bonding and cognitive functions in 19 Finnish families (n = 343 members) with professional musicians and/or active amateurs. All family members were tested for musical aptitude using the auditory structuring ability test (Karma Music test; KMT) and Carl Seashores tests for pitch (SP) and for time (ST). Data on creativity in music (composing, improvising and/or arranging music) was surveyed using a web-based questionnaire. Here we show for the first time that creative functions in music have a strong genetic component (h2 = .84; composing h2 = .40; arranging h2 = .46; improvising h2 = .62) in Finnish multigenerational families. We also show that high music test scores are significantly associated with creative functions in music (p<.0001). We discovered an overall haplotype association with AVPR1A gene (markers RS1 and RS3) and KMT (p = 0.0008; corrected p = 0.00002), SP (p = 0.0261; corrected p = 0.0072) and combined music test scores (COMB) (p = 0.0056; corrected p = 0.0006). AVPR1A haplotype AVR+RS1 further suggested a positive association with ST (p = 0.0038; corrected p = 0.00184) and COMB (p = 0.0083; corrected p = 0.0040) using haplotype-based association test HBAT. The results suggest that the neurobiology of music perception and production is likely to be related to the pathways affecting intrinsic attachment behavior.

Not too much too say, as I am admittedly an ass for music.
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Stone blades already 500,000 years ago.

Found at Remote Central, original news from Science Now.

This is a most interesting news and review for those of us who are interested in the formation of Humankind. In the past blade-making abilities were considered something somehow definitory of what meant to be Homo sapiens. Eventually blade tools associated with Neanderthals were discovered too and it was also acknowledged that many Sapiens cultures did not use blades altogether anyhow. The use of this technology is anyhow quite definitory of the Upper Paleolithic of West Eurasia.

Recent research anyhow has been pushing back this technology: to 380,000 in West Asia and 300,000 in Europe. Now the record of antiquity has been beaten by a discovery in Kenya that is dated to more than 500,000 years ago (509-543,000 BP)

The revealing artifacts

It must be mentioned that H. neanderthalensis and H. sapiens are not that old, they are generally believed to be some 200,000 years old as species, maybe less in the case of H. sapiens.

So who made them? Apparently our direct ancestor Homo heidelbergensis, whose remains (sometimes described as H. rhodesiensis) have been found in the same part of the Kenyan formation. In the case of the later European blades it would be H. antecessor, the direct ancestor of Neanderthals, while it is not obvious who would be responsible for the West Asian ones, of intermediate age.

One factor that is anyhow underlined is the last dramatic expansion of brain size in the human lineage about 600,000 years ago, which may have been responsible for a major shift in human intelligence, allowing for more complex achievements among our ancestors and extinct relatives.
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Of mice, men... and astrocytes

This is an interesting breaktrhough in neuroscience: US researchers have found that what really separates human brains from those of mice and rats, and probably from those of other rather intelligent (and certainly big-brained) animals as elephants, is not our neurones (identical) but the other brain and spinal cells: the astrocytes.

Astrocytes have been long thought to be mere support units in brains. One of the reason is that they do not communicate via electrical signals and therefore are hard to listen to. But what is been now discovered is that they actually communicate with neurons via calcium exchanges and that, importantly, human brains have unique types of astrocytes (laminar ones) and also that other common types are larger and maybe more sophisticated.

Full story in Science Daily.
Original paper: N. Oberheim et al., Uniquely Hominid Features of Adult Human Astrocytes.
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Intelligence, quality wiring and inheritance

From Science Daily. Original paper: Ming-Chang Chiang et al., Genetics of Brain Fiber Architecture and Intellectual Performance, Journal of Neuroscience, 2009.

UCLA researchers have discovered that intellectual performance is strongly correlated with the quality of the mieline covering of neuronal axons in the brain. Which in turn is strongly dependent on genetics.

For starters, mieline is the isolation layer around the "cables" (axons) in our brain and nerves. While neurons have many sinapsis (connections with other nearby neurones), they have one or two longer extensions called axons, which are the "cables" of our nervous system, brain included.

When axons' mieline is thick and therefore provides a good quality isolation, the neuronal signal is stronger and clearer. Instead, when mieline is thinner, the electrical isolation is worse and the neuronal signal weaker. The first case provides for good intelligence, while the latter does not; additionally bad mieline covering is also related to mental illnesses like autism and alzheimer. Mieline thickness also shows a U-shaped pattern in life that is optimized for middle age (the acmé of classical Greeks, located around the age of 40), what explains increase and decrease of intellectual prowess with age.

The UCLA team compared pairs identical twins (natural "clones") and normal syblings, finding more marked differences in mieline quality among the latter, all which correlated with intelligence. This seems to support a genetic background for these differences, as regular syblings share only c. 50% of the genes that are variable in humans (can be more or less but around that median figure anyhow), while identical twins share virtually 100% of their genes.

I find this interesting because the main classical anthropometrical correlation with intelligence used to be brain size (though independent for each gender) but many of us suspected that size was not the only thing that mattered. This in fact comes to prove that the quality of wiring, something that cannot be measured in cubic centimeters of cranial capacity, also influences intelligence strongly. It will be surely long before we can discover other such "design" factors (mieline quality being again a relatively easy to measure element, yet only now studied), things like the design of the neuronal network itself, probably a less genetic and more plastic one, organized largely in life by experience, but I'm sure such factors are acting right now. Of course the quality of the materials is influential, maybe fundamental, but how they come to be organized, something that only happens within life, which is surely as dependent on education, general experience and access to knowledge, also matters. The best computer of Earth, if only programmed to add 2+2 won't be able to do anymore, while the worst one can surely do much more than that with due attention.
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