neuroscience
neurophilosophy | February 27, 2008[Introduction]
McKemy et al (2002) used whole-cell patch clamping and calcium imaging to record the responses of cultured rat trigeminal ganglion neurons to cold temperatures and various cooling compounds. They found that the cells respond to menthol and cold with an increase in intracellular calcium ion concentration, and that these stimuli activate non-selective cation channels which are highly permeable to calcium. The currents measured were also found to be outwardly rectifying (i.e. much larger at positive than at negative holding potentials). Similar results were obtained from DRG…
neurophilosophy | February 26, 2008
Below is the introduction to my third and final piece of coursework, an essay entitled Multiple roles for Transient Receptor Potential Melastatin 8 (TRPM8) in cold thermosensation. This time, I discuss three recent studies which have contributed significantly to the understanding of the mechanisms by which nerve endings in the skin detect cold stimuli. I'll post the rest of the essay over the next few days, in 3 or 4 parts. The papers I discuss will be listed as references after the discussion section.
Summary: Here I discuss three recent studies which have contributed significantly to the…
neurophilosophy | February 23, 2008
(Cartoon by Greg Williams, from Wikipedia)
The term hyperthymestic syndrome was proposed by James L. McGaugh, a neurobiologist at the University of California, Irvine, and his colleagues, following their case study of the woman known as A.J. (The study was published in the journal Neurocase, and is available as a PDF; there's also this story on NPR.)
Now in her mid-40s, A.J. contacted the researchers, telling them about her "non-stop, uncontrollable and totally exhausting" autobiographical memory. While researchers have been fortunate enough to study a number of amnesic patients (see…
neurophilosophy | February 22, 2008
In an article called Patterns, published in the NY Times earlier this month, neurologist and author Oliver Sacks discusses the geometric visual hallucinations which occur during the migraine auras that he has experienced since early childhood.
Sacks explains that the hallucinations occur as a result of waves abnormal electrical activity sweeping across the visual cortex, and that they reflect the cytoarchitectonics of that part of the brain and the complex patterns of activity within it.
He goes on to speculate that, because this cellular activity is universal, it forms the basis of art and…
neurophilosophy | February 21, 2008In an article from last Saturday's Guardian, Rick Hemsley describes his experience of Alice in Wonderland Syndrome, the neurological condition in which the perception of one's body is distorted:
Floors either curved or dipped, and when I tried walking on them, it felt as though I was staggering on sponges. When I lay in bed and looked at my hands, my fingers stretched off half a mile into the distance.
...my symptoms just got worse. Everything was now distorted, all the time. Walking down the road, parked cars appeared the size of Corgi models, while I'd feel disproportionately tall. At…
terrasig | February 20, 2008Following the second terrorist action against UCLA's Dr Edie London and her other research colleagues, and the outcries of support that ensued, the institution is taking bold and well-justified action. This just in from Americans for Medical Progress:
UCLA is suing to protect researchers from animal extremists
Legal action follows attempted firebombings and harassment
Phil Hampton, e-mail
(310) 206-1460
UCLA is suing extremists to stop a campaign of terrorism, vandalism and menacing threats directed at faculty and administrators who conduct or support research involving laboratory animals…
neurophilosophy | February 19, 2008Here's some fascinating footage from 1942, showing Drs. James Watts and Walter Freeman performing a prefrontal leucotomy. The footage accompanies a short article called Lobotomy Revisited, and, like last week's trepanation film clip, is not for the squeamish.)
The procedure shown in the film is the Freeman-Watts Standard Procedure, which had been in use since 1936. This is different from the "ice-pick" lobotomy, which Freeman began to perform in 1945; it more closely resembles the original procedure of the Portugese neurosurgeon Egas Moniz.
neurophilosophy | February 19, 2008As I mentioned recently, Alvaro has taken over as organiser of Encephalon, and he's just posted the latest edition of the carnival, which has two dozen entries on a wide of variety of neuroscience topics. I especially like this one about the hidden neuroanatomical images in Renaissance paintings (or lack thereof).
The next edition of the carnival will be at Mind Hacks on 3rd March. If you'd like to contribute, send your links to encephalon{dot}host{at}gmail{dot}com.
clock | February 18, 2008Science Cafe on Teenage Brains :
Teenagers sometimes act as though they were from a different planet. On Tuesday February 19, the Museum of Natural Sciences will host a science cafe entitled "Altered States: Inside the Teenage Brain" at Tir Na Nog in Raleigh at 6:30p.m. The session will be led by Wilkie Wilson, Duke professor and director of BrainWorks, a program for brain research and education. Wilson studies the effects of drugs on learning and memory, and has helped write several books on teenage drug use. RSVP to Katey Ahmann by Monday, February 18.
terrasig | February 15, 2008Apologies that I've been a bit preoccupied to put up my own content last night and today. In the meantime, I must direct you to an excellent ethics discussion by the always insightful Prof Janet Stemwedel on the research program led by Dr Edythe London, the UCLA researcher who has been terrorized personally by the Animal Liberation Front.
Janet's thoughtful analysis of this situation exemplifies why she is one of the leading bioethics commentators on the web today. I share Janet's concern that the public has been unusually silent in response to the attacks on Dr London.
terrasig | February 15, 2008This just in tonight from the NIH National Institute on Drug Abuse for those looking for a Ph.D.-level position outside of the laboratory:
NIDA seeks Molecular Biologist to Direct NIDA Program in Molecular Neurobiology: Under Represented Minorities Are Encouraged to Apply.
The DHHS and NIH is an Equal Opportunity Employer
Health Scientist Administrator, GS-601-13/14 NIDA
Salary Range: $82,961.00 -$127,442.00 USD per year
Location: Rockville, MD 20892
Open Period: Thursday, February 14, 2008 to Sunday, March 23, 2008
Job Announcements: NIDA-08-237161-MP and NIDA-08-237161-DE
Major Duties:…
omnibrain | February 15, 2008Enjoy!
In the hospital the relatives gathered in the waiting room, where their family member lay gravely ill.
Finally, the doctor came in looking tired and somber.
"I'm afraid I'm the bearer of bad news," he said as he surveyed the worried faces.
"The only hope left for your loved one at this time is a brain transplant. It's an experimental procedure, very risky but it is the only hope. Insurance will cover the procedure, but you will have to pay for the brain yourselves."
The family members sat silent as they absorbed the news. After a great length of time, someone asked, "Well, how much…
terrasig | February 12, 2008Last week, we discussed the cowardly terrorist act toward UCLA's Dr Edythe London which was then expanded upon quite forcefully by Mark Hoofnagle at his denialism blog.
While we spend a fair bit of time around these parts questioning the leadership of the US national health agency, this statement of response from NIH is quite good:
On Tuesday, February 5, an incendiary device ignited at the front door of the home of Dr. Edythe London, an NIH-supported senior scientist and professor in the David Geffen School of Medicine at UCLA. This domestic terrorist act against a scientist who has…
omnibrain | February 9, 2008To reduce the severity of his seizures, Joe had the bridge between his left and right cerebral hemispheres (the corpus callosum) severed. As a result, his left and right brains no longer communicate through that pathway. Here's what happens as a result:
j7uy5 | February 7, 2008Zyprexa Adhera is a new formulation of
href="http://zyprexa.com/index.jsp">Eli LIlly's
antipsychotic medication,
href="http://www.nlm.nih.gov/medlineplus/druginfo/medmaster/a601213.html">olanzapine.
It contains the same active ingredient as the pills, but it
is a long-acting injection. It is supposed to last two to
four weeks.
There is not a lot of specific information available yet. It
is not on the market yet, either. The milestone is that in
was just recommended for approval by the
title="Food and Drug Administration">
href="http://www.fda.gov/">FDA.
Background:…
neurophilosophy | February 4, 2008
Technology blogger Robert Scoble attended the World Economic Forum at Davos, and made quite a few video recordings of the conversations he had with various people while he was there, which he has uploaded to Qik.
In this film, Scoble talks to the Brazilian neuroscientist Miguel Nicolelis, who discussed his recent experiments in which a monkey with a brain-computer interface implanted into its motor cortex controlled the movements of a robot that was located more than 7,000 miles away.
Nicolelis presented his results during a session called Redefining the…
neurophilosophy | February 4, 2008
[Introduction|Part 2]
It is well established that synaptic strengthening involves the recruitment of AMPARs to the postsynaptic membrane. However, the subunit composition of the receptors has not been investigated closely, so the studies discussed here allow for refinement of this basic model, as they all show that synaptic strengthening involves the incorporation of Ca2+-permeable GluR2-lacking AMPARs to the postsynaptic membrane of active or recently-potentiated synapses.
The studies further demonstrate that synaptic plasticity involves switching of AMPAR subtypes. Bellone and Luscher…
purepedantry | February 4, 2008How is tool use encoded in the brain?
Most movements involving tools involve the complex manipulation of objects in space, and it is possible that they could represented in the brain in this way -- i.e. as objects in space. On the other hand, the purpose of tools is to extend the range of motions available to the body, so it is also possible that tool use could be encode as an extension of the body representation onto the tool.
Some cunning work by Umilta et al. at the University of Parma shows the second option is the case. The brain represents tools by incorporating them into…
neurophilosophy | February 2, 2008John Pezaris emailed me yesterday to say:
Last spring, you were kind enough to write an article for your Neurophilosophy blog covering my research into restoring sight to the blind, following the publication of our scientific paper in the Proceedings of the National Academy of Science. Your article was one of the best ones written: I was really impressed at how accurately you summarized our work.
I'd like to bring to your attention that the project has been named one of the 10 finalists for the Saatchi and Saatchi Award for World Changing Ideas.
Congratulations to John Pezaris and…
neurophilosophy | February 1, 2008Following on from the introduction, I now discuss a number of recent studies which demonstrate that synaptic strengthening in different regions of the mammalian brain requires the incorporation of Ca2+-permeable GluR2-lacking AMPA receptors into the postsynaptic membrane of active or newly-potentiated synapses.
Neurotransmitter release regulates GluR1 levels at the postsynaptic membrane
Harms et al (2005) inhibited neurotransmitter release from specific subsets of cultured hippocampal neurons by transfecting individual cells with the tetanus toxin light chain tagged with cyan fluorescent…