neuroscience
clock | August 2, 2006When I saw this article in SEED Maagazine, I had only one thought - Mokie-Koke!
Readers of science fiction know what I am talking about. I was reminded of "The Merchant's War", the 1984 sequel to the 1952 brilliant dystopia "The Space Merchants", the book that beat "1984" and "Brave New World" in its accuracy of prediction. The initial novel - one of the all-time-greats of the genre, was written by Frederick Pohl and Cyril Kornbluth. The sequel, 32 years later, was written by Pohl alone.
It's been at least 15 years since I last read The Merchants' War, but if I remember correctly, each…
cortex | August 1, 2006After reading articles like this (or this or this or this), I can't help but wonder what's happening to the brains of Iraqis, Palestinians, Israelis and Lebanese. After all, neuroscience now knows that chronic stress is toxic. When your brain is constantly suffused with stress hormones (usually glucocorticoids), neurons die and aren't replaced. Dendritic growth slows down. You have fewer synaptic proteins. Your hippocampus begins to wither and shrink. Even if you are just a baby in your mother's belly during the war, you are still born with reduced levels of neurogenesis.
The worst part of…
j7uy5 | July 31, 2006When I finished residency, I took a position at a University
clinic north of town. In order to get there, I had to cross a
bridge over a river. I drove over that bridge about 100 times
before the first snowfall.
On the first snowy day, while driving over the bridge, I noticed a
sign. The sign warned that the bridge could be icy.
Prior to that first snowy day, I had not noticed the sign.
Fast-forward to the present day. A
title="Quirky Outtakes" href="http://quirkynomads.com/wpt/">thoughtful
reader
sent a suggestion that I write about the subject of
title="Wikipedia link"…
neurontic | July 30, 2006 While we're on the subject of brain size, I wanted to share another interesting Temple Grandin theory. In Animals in Translation, Grandin suggests that we humans may be suffering from a species superiority complex. While she agrees that domestication was responsible for a 10 percent reduction in brain size in dogs, she contends that the civilizing process cut both ways. Taming wolves had a profound effect on the evolution of the human brain, according to Grandin.
Recent scientific findings suggest that human-wolf cohabitation began as long as 100,000 years ago. If these findings are correct…
cortex | July 29, 2006Well, sort of. A well-timed insult by Materazzi also helped. But the WSJ reports today that several members of the Italian team used neurofeedback earlier this year to help hone their powers of concentration:
In February, months before the tournament started, some of Italy's best soccer players, including a handful who would later play in the Cup, began spending much of their practice time in a small room in Milan furnished with six luxury leather recliners facing a glass wall.
On the other side of the glass Bruno De Michelis, head of the sports science lab for AC Milan, one of the country's…
neurotopia | July 28, 2006Amyotrophic Lateral Sclerosis is a devastating disease that claims the upper and lower motor neurons, and ultimately the lives of most patients within 3-5 years of diagnosis, usually from respiratory failure. Patients lose control of voluntary muscles as the pathways that innervate them degenerate. Lou Gehrig and Stephen Hawking are two famous ALS patients.
Now a group suggests that antisense oligonucleotide therapy may be used to effectively treat some forms of the disease.
Some forms of ALS are heritable. A subset of these cases are caused by a mutation to the enzyme superoxide…
purepedantry | July 26, 2006...depression.
This is related to something they make medical students memorize. When someone comes in with hypertension, it is always good to check whether the person has renal artery stenosis because this is one of the few causes of hypertension we can actually fix. Renal artery stenosis results in hypertension because your kidneys secrete hormones that are involved in maintaining your blood pressure. How much hormones they decide to secrete is determined largely by the blood pressure that is felt by your kidneys; thus, when you block blood flow to the kidneys, they become convinced…
cortex | July 26, 2006The NY Times Magazine described an interesting study that I'd never heard about before:
A study of French youngsters adopted between the ages of 4 and 6 shows the continuing interplay of nature and nurture. Those children had little going for them. Their I.Q.'s averaged 77, putting them near retardation. Most were abused or neglected as infants, then shunted from one foster home or institution to the next.
Nine years later, they retook the I.Q. tests, and contrary to the conventional belief that I.Q. is essentially stable, all of them did better. The amount they improved was directly related…
cortex | July 26, 2006Small Gray Matters has an insightful post on the recent mirror neuron debate here at Scienceblogs. While I think a dose of skepticism is always helpful (especially when big mysteries like "empathy" and "theory of mind" are being tossed around), Small Gray Matters offers a persuasive defense of this circuit in the motor cortex:
Mirror neurons offer what is clearly the most plausible current model of imitative behavior, which isn't a trivial matter, since imitation turns out to be pretty rare in the animal kingdom. For another, it wasn't all that long ago that people were pretty skeptical about…
neurontic | July 26, 2006Okay, I know I promised the next entry would be devoted to Temple Grandin's views on language -- a subject well worth exploring -- but I've found myself distracted by some of my other reading this week. (So much to read, so little time.) Be assured, we'll delve into "Grandin on Language" at a later date. Today, I find my thoughts once again turning to the teaspoon of gray matter separating the male and female brain. ("When it comes to brains, does size really matter?) I revisited this entry after the Tangled Bank Carnival and found myself no less irate over Terence Kealey's pseudoscientific…
neurotopia | July 25, 2006Mixing Memory brings up some excellent points regarding mirror neurons in primates, and Frontal Cortex follows up with his thoughts. To both of them I say "bravo, but your skepticism probably doesn't go far enough".
We give Rizzolatti et al too much credit with their conclusions. After all, they've only demonstrated the existence of mirror neurons in monkeys. Due to the obvious inherent difficulties associated with recording from human neurons in vivo, no one has yet (to my knowledge) published anything that demonstrates the existence of mirror neurons in people. Instead, we stick…
cortex | July 24, 2006Mixing Memory tosses a helpful bucket of cold water on the mirror neuron frenzy. The post focuses on the hypothesis that mirror neurons were a crucial ingredient in the development of human language. While I think much of the skepticism is well deserved - mirror neurons remain a mysterious bunch of cells - I think Mixing Memory neglects to mention one important bit of evidence that supports the mirror neuron-language connection.
Specifically, Giacomo Rizzolatti (the godfather of mirror neuron research) has shown that mirror neurons can be activated by fragments of language that are about…
clock | July 21, 2006Survey questions themselves may affect behavior:
Simply asking college students who are inclined to take drugs about their illegal-drug use in a survey may increase the behavior, according to a study that's making researchers understandably nervous.
"We ask people questions, and that does change behavior," study co-author Gavan Fitzsimons, a marketing professor at Duke University's Fuqua School of Business, said Thursday. The provocative effect, he added, can be "much greater than most of us would like to believe."
Read the rest, it is quite interesting. My first thought - can frequent…
purepedantry | July 19, 2006Now I study oligodendrocyte development, and if you ask me they are a truly unappreciated cell type. Here is yet one more piece of evidence: synapses have been detected between neurons and oligodendrocytes in CA1 of the hippocampus AND these synapses can undergo a kind of LTP.
Glial cells in the central nervous system (CNS) constitute a heterogeneous population of cell types. Macroglia-like NG2 cells express the chondriotin sulfate proteoglycan NG2 and have been described as oligodendrocyte precursor cells (OPCs) or given other names. NG2 cells in the CA1 area of the hippocampus receive…
neurotopia | July 19, 2006The difficulty with treating spinal cord injuries arises from a number of factors. Firstly there is the primary damage to the axons of the spinal cord itself, resulting in mechanical damage that can inhibit neurotransmission and transport of cellular material to and from the distal cord. The damaged cord must also compensate for secondary damage such as the generation of free radicals, a lack of oxygen to the affected area (anoxia), glial scarring, and a host of other issues.
Your typical spinal neuron looks like this.
(Image snagged from http://www.steve.gb.com). The axon is a long…
clock | July 17, 2006The second edition of Encephalon, the neuroscience carnival, is up on Pure Pedantry.
purepedantry | July 16, 2006Evil Monkey from Neurotopia posts on face blindness or prosopagnosia, and how they have found a gene that results in a heritable form. They have not, to my knowledge, found a gene for why I can't remember the girl who woke up in my bed's name. He also has an article on pesticide-induced Parkinson's disease complete with nifty histology. OOOOOOoooo...neat.
Shelley at Retrospectacle covers paralyzed rats that can walk after stem cell therapy. Ummm...Senators, maybe you should keep that in mind when you vote this week. She also provides yet another reason not to go to Kiss concerts: you may…
neurotopia | July 16, 2006Unfortunately I'm stuck with the press release on this one, my government-access VPN doesn't seem good enough to get me this article at home. Face blindness, or prosopagnosia, is a condition where a person is unable to recognize another person by their face and must rely on other features, such as gait, hair, voice, or other features.
Recognition of faces can be disrupted by damage to the fusiform gyrus of the temporal lobe. Here, it seems the researchers have found a heritable genetic defect that leads to face blindness.
The 14 participants reported that they experienced uncertainty in…
neurotopia | July 16, 2006Shelley mentioned a study last week that suggested more and more young people are getting Parkinson's Disease, and she wondered whether there was any utility in blaming our industrialized society based on the fact that certain compounds we produce can induce Parkinsonian symptoms. Let's start by giving a brief overview of the systems involved before we attempt to answer that question.
The substantia nigra contains a collection of dopaminergic neurons that project to the striatum. Integrity of this pathway is essential for normal motor function, although this nigrostriatal system is capable…