Posts tagged ‘brain’


Intelligence Is in the Genes, but Where?

You can thank your parents for your smarts—or at least some of them. Psychologists have long known that intelligence, like most other traits, is partly genetic. But a new study led by psychological scientist Christopher Chabris of Union College reveals the surprising fact that most of the specific genes long thought to be linked to intelligence probably have no bearing on one’s IQ. And it may be some time before researchers can identify intelligence’s specific genetic roots.

Chabris and David Laibson, a Harvard economist, led an international team of researchers that analyzed a dozen genes using large data sets that included both intelligence testing and genetic data.

In nearly every case, the researchers found that intelligence could not be linked to the specific genes that were tested. The results are published online in Psychological Science, a journal of the Association for Psychological Science.

“In all of our tests we only found one gene that appeared to be associated with intelligence, and it was a very small effect. This does not mean intelligence does not have a genetic component. It means it’s a lot harder to find the particular genes, or the particular genetic variants, that influence the differences in intelligence,” said Chabris.

It’s important to remember that we aren’t flowers, that intelligence is immensely more complex than the color of petals. There isn’t an “intelligence gene,” but rather a bunch of genes that influence it both individually and in cooperation with others. In addition, we aren’t positive on how the nurture-vs-nature relationship works in either. 

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jtotheizzoe:

The Connectome Debate: Is Mapping the Mind of a Worm Worth It?

The connectome-related skepticism has been ramping up lately. So you mapped the complete neural network of a tiny worm (C. elegans, above) … so what? So you draw some pretty brain structures that don’t provide neuron by neuron detail … so what?

Ferris Jabr has a great write-up of the “so whats” and the “this is what” at SciAm. Want to get up to date on the connectome debate? Start here.

Because a lone connectome is a snapshot of pathways through which information might flow in an incredibly dynamic organ, it cannot reveal how neurons behave in real time, nor does it account for the many mysterious ways that neurons regulate one another’s behavior. Without such maps, however, scientists cannot thoroughly understand how the brain processes information at the level of the circuit. In combination with other tools, the C. elegans connectome has in fact taught scientists a lot about the worm’s behavior; partial connectomes that researchers have established in the crustacean nervous system have been similarly helpful. Scientists are also learning how to make connectomes faster than before and to enhance the information they provide. Many researchers in the field summarize their philosophy like this: “A connectome is necessary, but not sufficient.”

So it’s taught us a bit about the workings of the worm, but maybe not everything. Will it translate to elucidating the workings of the human brain? Time will tell. Good read.

(via Scientific American)

A way to look at how certain stimulant drugs affect your central nervous system…

jtotheizzoe:

…using a GIF of water filling up a sink as an analogy for dopamine:

I love simple explanations.

(via @stevesilberman)



neurosciencestuff:

All vertebrates’ eyes emerge from a single group of cells, called the eye field, located in the middle of the brain. The eye field cells evaginate to form two optic vesicles, which eventually give rise to two retinas, one on either side of the brain.

Eyes Emerge

Top image: In a ~5 somites embryo, eye field cells are stained red, and forebrain cells are outlined in green (upper left). A few hours later, in a ~10 somites embryo, the eye field (green) separates into two optic vesicles. At the same embryonic stage, the dorsal telencephalon, which sits atop the evaginating eyes, is labeled blue (bottom left). In both of these images, a midline positioned cross outlines the apical surface of the optic vesicles and the ventricular space. The animation follows the development of this same surface as the eyes emerge from the brain.

Sunrise in the Eye

Bottom image: Once the basic shape of the eye is specified, cells within the optic cup differentiate, populating the retina with neurons that sense light and refine the visual information before it is transmitted to the brain. In fish and amphibia, retinal stem cells are maintained throughout the animal’s lifetime in a stem cell niche located adjacent to the lens (yellow). Here in situ hybridization of a zebrafish eye (from a ~ 3-day-old larva) reveals gene expression patterns that distinguish retinal stem cells (red) from the cells that are becoming neurons (purple). By comparing gene expression patterns within the retinal stem cell niche in normal and mutant eyes, we gain insight into how stem cells turn into neurons.

Eyes are not only amazingly complex, but are reducibly so!



sciencesoup:

The Science of Linguistics

Linguistics is by definition the scientific study of language, but it’s been long debated whether it is a “soft” science. Science is the systematic study of the physical and natural world through observation and experiment, and hard sciences are generally perceived as more rigorous and accurate—i.e., natural, physical and computing sciences. “Soft” sciences are usually social, but linguistics seems to blur the line between the two—language is a social construct, but it’s also a complex, ever-evolving natural phenomenon, made up of dozens of sounds that combine to create thousands of words in thousands of different languages. Linguists study the use of language almost like animal behaviour is studied, and in recent years, modern linguistics has gravitated towards a “hard” science approach, focusing on accuracy, objectivity, and empirical data. Its many specialised subfields help enforce the rigour, such as phonology (the study of sound), syntax (the study of sentences), and semantics (the study of meaning), and linguistics also crosses disciplines to study the psychology, the neuroscience, and even the computer science of languageenabling the creation of language databases to analyse written and spoken patterns. However, hard sciences also have the capability to draw strong conclusions and make accurate predictions, and linguistics often deals with too many non-quantifiable variables to achieve either of these. For now, linguistics remains a soft science—but that doesn’t make it any less fascinating. After all, without language, we wouldn’t be able to communicate scientific ideas at all.

(Image Credit: 1, 2)

I only have some historical background knowledge on linguistics, mostly on how it shows human migrations, but the entire field seems fantastically interesting.


fuckyeahmolecularbiology:

Retinal Fireworks

Retinal ganglion cells transmit signals from the rods and cones in the eye to the brain. The retinal ganglion cells shown here have the extraordinary property that their dendrites all point in a single direction. Remarkably, these neurons respond best to objects moving in the direction that the cells “point.”

In this particular image, a mouse retina is seen with “J” retinal ganglion cells marked by the expression of a fluorescent protein. Of course, in real eyes it’s not that simple – the millions of other neurons that these are entangled with are not marked, and thus appear invisible. The image was obtained with a confocal scanning microscope, and pseudocoloured.

Part of the Cell Picture Show’s amazing Brainbow series.


valuablelesson:

6th Prize – Thomas J. Deerinck

National Center for Microscopy & Imaging Research – University of California – San Diego – La Jolla, California, USA

Specimen: Rat retina astrocytes and blood vessels (160x)
Technique: Fluorescence and Confocal

Astrocytes (yellow) are glial cells in the brain and spinal cord. They are so named for their “star” shape. They are the most abundant types of cell in their cell and give it its physical structure. Among other biochemical and metabolic processes, they are associated with neural synapses that help the brain communicate with itself, and other parts of the body.

(The red and blue stains are blood vessels that supply the area with oxygen and nutrients.)