neuroscience
neurophilosophy | November 21, 2007[Introduction|Part 2|Discussion]
Tojima et al (2007) find that the growth cone's response to attractive guidance cues requires asymmetrical vesicle transport and exocytosis. They cultured dorsal root ganglion (DRG) cells from embryonic chicks, and produced localized elevations in calcium ion concentration on one side of the growth cone by photolytic release of the caged calcium ion compound DMNT-EDTA. In cells cultured on a substrate of cell adhesion molecule L1, this causes calcium-induced calcium release (CICR), and elicits a turning response in the direction of the calcium signal. In…
omnibrain | November 21, 2007Everyone has been talking about stem cells in the last couple days. Here's something to offend most of you - Christopher Reeve eating fetuses for their Stem Cells. Enjoy ;)
Now that you are probably horribly offended about something or other here's why I'm posting this video now:
Now paralyzed people can eat their own stem cells to become superpeople!
neurophilosophy | November 20, 2007[Introduction|Part 3|Part 4]
Lopez-Bendito et al (2006) show that pathfinding of thalamocortical axons (TCAs) requires the formation of a permissive corridor through non-permissive territory, and that this corridor is generated by cells which undergo a tangential migration from the lateral ganglionic eminence (LGE).
TCAs arise in the dorsal thalamus, and follow a stereotyped pathway into the developing neocortex. Initially, they are repelled by Slit 1 and Slit 2 expressed in the hypothalamus. They extend rostrally into the telencephalon and turn sharply before extending dorsolaterally to…
neurophilosophy | November 19, 2007
Dylan T. Burnette/ Nikon Small World.
The remarkable specificity of neuronal connectivity depends on accurate axon pathfinding during development. Pathfinding involves the detection of guidance cues in the environment by the growth cone, a motile chemotactic structure at the leading tip of the extending axon.
The growth cone was discovered over 100 years ago by Santiago Ramon y Cajal, the father of modern neuroscience. Cajal's description of the growth cone (or cono de crecimiento) has not been bettered:
From the functional point of view, one might say that the growth cone is like a…
sb admin | November 19, 2007I couldn't wait for Multimedia Friday to post this video, it's just too funny.
I Am the Very Model of a Psychopharmacologist is set to Gilbert and Sullivan's classic song with animation. Created by Stephen M Stahl, MD, PhD, of the Neurosciences Education Institute, Adjunct Professor of Psychiatry at the University of California San Diego, author of Essential Psychopharmacology. Credentials for neuropsychopharmacological hilarity.
j7uy5 | November 17, 2007
rel="tag">Simon N. Young, PhD, the Editor-in-chief
of the Journal of
Psychiatry and Neuroscience, has written an editorial: How
To
Increase Serotonin In The Human Brain Without Drugs.
In is
published in this month's edition of the Journal of
Psychiatry and Neuroscience.
The Journal is an open-access journal, so anyone can read it.
The PDF is
href="http://www.cma.ca/multimedia/staticContent/HTML/N0/l2/jpn/vol-32/issue-6/pdf/pg394.pdf">here.
I have to admit, I was both surprised and skeptical when I first saw
this. Although there are many converging lines of evidence
associating…
neurophilosophy | November 16, 2007
Synaesthesia is a condition in which stimuli of one type evoke sensations in another sensory modality. For example, hearing particular sounds might evoke strong sensations of colour or (more rarely) words might evoke strong tastes in the mouth.
In The Hidden Sense, social scientist Cretien van Crampen investigates synaesthesia from an artisitic and scientific perspective. He interviews a number of synaesthetes, and finds that none of them considers their condition to be an impairment. He also describes the profound influence that synaesthesia has had on artists such as Kandinsky and van Gogh…
purepedantry | November 16, 2007
I wrote before about how there has been a bit of a debate about whether the hippocampus is involved in encoding spatial maps or is involved more generally in relational memory. Well, the argument for general relational memory just got a big boost. Johnson and Redish published a paper in the Journal of Neuroscience showing that rats mentally project forward to parts of a maze they haven't visited yet. It is solid evidence for prospective coding in the hippocampus.
Just to recap that a little bit, for many years we have known that the hippocampus is involved in encoding new memories…
neurophilosophy | November 15, 2007
At the Society for Neuroscience meeting in San Diego last week, a group of researchers presented data on a speech prosthesis which they say could soon enable a paralyzed man to talk again.
The device, which consists of 3 gold recording wires, was implanted into the brain of Eric Ramsey, who was completely paralyzed in a car accident 8 years ago. Ramsey is said to be "locked in" - he is fully conscious but is unable to communicate in any way.
The implant is located 6mm below the surface of Ramsey's brain, in a part of the left premotor cortex, where it records the activity of 41 cells…
omnibrain | November 13, 2007Just about every election cycle and Superbowl Marco Iacoboni and his lab do some sort of neuroimaging study to determine what people are actually thinking about the political candidates or their teams. Every time these studies come out you can hear the popular press cheering and smiling while you can hear scientists and bloggers cringing in disgust. The most recent study, instead of being published in a peer review journal, was published in the NYTimes. Head over there to give it a read before you continue on.
People cite many reasons to be doubtful of these studies, some complete nonsense…
neurophilosophy | November 9, 2007
The Los Angeles Times reports on "Robo-moth", a cleverly designed contraption, built from cheap off-the-shelf parts, which was presented at the Society for Neuroscience meeting in San Diego earlier this week.
Robo-moth is a 6-inch-tall wheeled robot to which attached tobacco horn moth has been attached. A microelectrode inserted into the insect's brain records the activity of a single visual motion detection neuron, which exhibits directional selectivity and which is involved in steadying the visual field during flight.
The moth is immobilized inside a cylinder covered with vertical stripes…
neurophilosophy | November 9, 2007
The cover of the current issue of Neuron features this brainland map, by Sam Brown, a cartographer based in New Zealand. Printed A3, A2 and A1 sized copies of the map can be purchased from Unit Seven.
...created from a reference photo of a real human brain which was used to build the 3D terrain. This digital elevation model was then used to create contour line data, relief shading and to plan where the roads and features should be placed for map compilation. Real New Zealand public domain data was then added for the surrounding islands.
I've just written an essay about Axon Turning…
neurophilosophy | November 8, 2007Today's New York Times contains a very good opinion piece about the benefits of physical exercise for maintaing and improving brain health, by Sandra Aamodt, editor-in-chief of Nature Neuroscience, and Sam Wong, an associate professor of molecular biology and neuroscience at Princeton.
There is good evidence that exercise can slow age-related cognitive decline. Specifically, it is known to improve the executive brain functions which control other cognitive processes, and which begin to decline in one's 70s. Executive function is better in elderly people who have remained athletic throughout…
neurophilosophy | November 7, 2007
Researchers from the National Institute on Aging in Baltimore have produced an "atlas" of the activity of nearly 17,000 genes in 5 different regions of the mouse central nervous system.
Using microarrays, the NIA team measured the levels of mRNA transcripts in the cortex, hippocampus, striatum, cerebellum and spinal cord. Samples were taken from young, middle-aged and old-aged mice of both sexes, and maintained on either a normal or a calorie restricted diet.
In this way, the transcriptome of each region, or the whole repertoire of mRNAs found in each region, was obtained. The…
j7uy5 | November 6, 2007
href="http://www.researchblogging.org/">
alt="Blogging on Peer-Reviewed Research"
src="http://www.researchblogging.org/public/citation_icons/rb2_large_gray.png"
height="50" width="80">The
researchers did fMRI
of brains of persons with
href="http://en.wikipedia.org/wiki/Borderline_personality_disorder"
rel="tag">Borderline Personality Disorder, before
and after psychotherapy. This was a small study, using a
design that would be difficult to use routinely, but it is
provisionally interesting. Difficult, because the patients
received 12 weeks of inpatient therapy (perhaps…
neurophilosophy | November 5, 2007
Washington Treasury Secret Service Bureau chief M. R. Allen acts as a subject in a demonstration of the polygraph test, at the U.S. Secret Service Men's Convention in 1941. (Image: Bettmann/ Corbis)
This week, the NPR Morning edition featured a three-part series on lie detection, which included a story about Daniel Langleben, a neuropsychiatrist at the University of Pennsylvannia who uses functional magnetic resonance to try and determine how brain activity differs when one is lying or telling the truth.
I attended a presentation by Langleben at the Wellcome Trust Centre for Neuroimaging…
neurophilosophy | November 5, 2007
Vaughan is recruiting participants for a study of the neuropsychology of hypnosis which he is involved in.
In the first stage of the research, participants will be asked to answer a series of short questionnaires and complete a short test, to determine the extent of their suggestibility (their willingness to believe and act upon the suggestions of others), which is closely related to one's 'hynotisablity'.
The study will be carried out at the Institute of Psychiatry in South London, and the first stage will take place on three consecutive Saturdays, beginning next weekend, on the 10th…
neurophilosophy | November 5, 2007Primate Diarist Eric has just posted the 35th edition of Encephalon, the neuroscience and psychology blog carnival.
My favourite posts this time round are the Neurocritic's examination of the purported discovery of the "neural basis for optimism", and Jake's description of two-photon fluorescence microscopy for in vivo imaging of neuronal activity. (There's no link to this latter post - Eric has linked twice to Jake's other submission, but this should be fixed soon.)
The next edition of Encephalon will be hosted by Noam at Brain in a Vat on November 19th. If you'd like to contribute, email…
neurophilosophy | November 4, 2007
The Brainloop brain-computer interface, demonstrated at the VisionSpace laboratory for perception and cognition at FH Joanneum, University of Applied Sciences in Austria. (Photo by Miha Fras, courtesy of Aksioma/ Institute for Contemporary Art, Ljubljana)
What will they think of next? First, there was the brain-computer interface for controlling Second Life avatars, and yesterday I mentioned a gig in which the music is controlled by the audience's brainwaves. Now, researchers from Austria and Slovenia have developed a device called Brainloop, which can be used to navigate in Google Earth:…
neurophilosophy | November 3, 2007James Fung, a musician and computer engineer at the University of Toronto, has developed a program that can convert EEG recordings into music.
Fung is involved in the Regenerative Brain Wave Music Project, which "explores new physiological interfaces for musical instruments."
As part of the project, he staged a concert in which the music and lighting were controlled by the audience's brainwaves.
There's more information, and some footage of the concert, in the film clip below.
[Via Mind Update]