neuroscience
cortex | September 14, 2006Over at the Loom, Carl Zimmer reflects on 18th century science, lightning, and the nervous system. The question of when scientists first realized that our nerves used the same stuff as lightning bolts - a completely outlandish idea - has long fascinated me. It's an empirical story in which two great Italian scientists - Count Alessandro Giuseppe Antonio Anastasio Volta and Luigi Galvani - engaged in a bitter argument about the interpretation of a classic experiment. Volta was right about the experiment, but Galvani was right about the biology.
The story begins in the early 1780's, when…
cortex | September 13, 2006From The Atlantic:
Studies indicate that Asian students achieve some of the highest scores in the world in math and science comparisons. However, owing to excessive focus on memorization, done solely for the purpose of passing tests, these gloomy idiot savants demonstrate surprisingly little practical know-how and often are unable to apply what they've learned. And this is the educational system we mistakenly aspire to, argues Alexandra Robbins, who traces the U.S. overachiever culture back to the President Reagan's 1983 Department of Education report "A Nation At Risk."
While I'd still…
cortex | September 12, 2006It's not that rich people sleep more hours per night - although they often do - it's that they are more efficient at using their time in bed. In other words, they are less likely to toss and turn. I wonder if this is because they can afford Ambien...
purepedantry | September 12, 2006GNIF Brain Blogger has a good article describing the DSM -- Diagnostic and Statistcal Manual of Mental Disorders -- that is used by psychiatrists to diagnose mental health issues of all types. Drawbacks and benefits are discussed.
In spite of some rather notable problems with the DSM -- for example, in earlier editions homosexuality was still listed as a mental disorder -- I have to sympathize with the people who write it. In contrast to most other areas, most psychiatric disorders are syndromic in nature and lacking in definitive lab tests. This makes diagnosing them an act of guessing…
purepedantry | September 11, 2006I talked earlier this year about a patient who recovered from a coma after 20 years. In that post, I discussed how -- with respect to the diagnostic criteria -- the difference between a persistent vegetative state and a minimally conscious state is the difference between someone who has only autonomic nervous activity and episodic conscious activity. In this way, someone who is in a minimally conscious state -- as that patient was -- still has the possibility for recovery even if recovery is very rare.
Here is another case of a woman in a persistent vegetative state discussed in the…
j7uy5 | September 11, 2006There is a lot of
information about
href="http://en.wikipedia.org/wiki/Vagus_nerve_stimulation"
rel="tag">vagus nerve stimulation as a treatment
for depression, that you can get from the latest New York Times article
(
href="http://www.nytimes.com/2006/09/10/business/yourmoney/10cyber.html?ex=1315540800&en=7877734ab451d64f&ei=5090&partner=rssuserland&emc=rss">Battle
Lines in Treating Depression, permanent link) on the subject.
Unfortunately, most of the good information is found by
following links. The article itself is pretty bad.
The author launched into a…
cortex | September 7, 2006Cognitive Daily brought my attention to an interesting study about consumers and health care. Simply put, Americans are terrible at knowing when we are getting good medical treatment. Our satisfaction with our doctors bears no relationship to how good our doctors actually are.
This shouldn't be too surprising. Psychologists and economists have long known that humans are bad judges of health and health care. As Amartya Sen pointed out several years ago, life expectancy is often inversely related to self-reports of sickness. Sen arrived at this outlandish conclusion after looking at the health…
cortex | September 6, 2006Over at Slate, Gregg Easterbrook proposes an audacious hypothesis: the rise of television viewing among infants is responsible for the current autism epidemic.
The idea is wholly speculative. No scientist has shown a link between autism and television, but so far as I could determine no scientist is working on this question, either--and maybe someone should be. Beginning in about 1980, TV watching in early childhood began to rise, coincident with the proliferation of affordable VCRs and cable channels offering nonstop cartoons and kids' shows. The child's brain is self-organizing in the first…
purepedantry | September 6, 2006I wrote earlier this week about evidence from electrode arrays that LTP occurs in vivo in behaving rats ("Rats, you behave!"). The paper showed that if you use an avoidance learning paradigm you can detect LTP in the hippocampus after one trial. The paper does not, however, necessarily prove that this LTP is actually necessary for learning (although there is a huge body of evidence in vitro that suggests that this is the case).
Another paper in Science rectifies that deficiency. Pastalkova et al. also show in Science that if we infuse an inhibitor to a particular enzyme into the rat…
cortex | September 6, 2006An excellent review has just been published in Nature Reviews Neuroscience on the relationship between enriched environments and the onset and severity of nervous system diseases. A consensus seems to be emerging: putting rodents in enriched environments - cages with space for foraging, toys and social interaction - not only delays disease but reduces the symptoms. The list of diseases for which this effect has been verified is staggering. It reads like a who's who of neural nightmares: Alzheimers, Huntington's, Parkinson's, epilepsy, stroke, traumatic brain injury, Fragile X syndrome and…
cortex | September 5, 2006Jerry Vlasak is a dangerous lunatic, a spokesman for domestic terrorists. He is also a trauma surgeon living in Woodland Hills:
Vlasak's views are so incendiary that he is banned from ever visiting Britain. He has been arrested on a Canadian ice floe, at a traveling circus, at a Rodeo Drive furrier. In La Cañada Flintridge, he once fended off a furious PTA mom while disrupting an elementary school fundraiser featuring circus animals.
Vlasak, a trauma surgeon who lives in Woodland Hills, takes his belief that animal life is as valuable as human to the extreme -- openly arguing that killing…
purepedantry | September 5, 2006My suspicion is that the people who know about neuroscience read the title of this and said: "Wow, Jake, there's a shocker. Tell us something we didn't know." Everyone else probably said: "Guh?" Therefore, I should probably explain why I think this finding is cool.
LTP or Long Term Potentiation is an experimental paradigm that is believed to simulate learning in vivo. In the paradigm, an exciting electrode and a recording electrode are placed into the brain of the animal, usually into an area called the hippocampus. The electrodes are position such that the action of the excitation…
j7uy5 | August 30, 2006One of the articles that I read, early in my career, that influenced
the way I think about neuroscience, was this one:
href="http://archpsyc.ama-assn.org/cgi/content/abstract/49/9/681">Caudate
glucose metabolic rate changes with both drug and behavior therapy for
obsessive-compulsive disorder
L. R. Baxter Jr, et. al., Arch Gen Psychiatry.
1992;49:681-689.
We used positron emission tomography to investigate local cerebral
metabolic rates for glucose (LCMRG1c) in patients with
obsessive-compulsive disorder before and after treatment with either
fluoxetine hydrochloride or behavior…
clock | August 29, 2006Yesterday, we were putting down media reports on a study that purports that dolphins are not intelligent despite behavioral studies and big brains. Today, NYTimes has a much better article arguing that manatees, despite their small brains, are more intelligent than previously thought.
It is a longish article but well worth reading. The idea is that manatees don't have too small brains, but overlarge bodies, and, since they are herbivores with no prey or predators, they do not need to reserve vast portions of their brains for tackling hunting and defense.
Brain size has been linked by some…
purepedantry | August 29, 2006The Neurophilosopher has a fabulous long post on the discovery of the neuron as the fundamental unit of the nervous system.
I would note when you get to the part about Ramon y Cajal that his picture of the neurons in a chick cerebellum formed the red banner for this site, and a picture of him is part of the green banner. He is my favorite neuroscientist. (For those of you who haven't noticed if you keep reloading the site you get a random banner. There are six.)
clock | August 28, 2006Where does one start with debunking fallacies in this little article? Oy vey!
Dolphins and whales are dumber than goldfish and don't have the know-how to match a rat, new research from South Africa shows. For years, humans have assumed the large brains of dolphins meant the mammals were highly intelligent.
No, we knew dolphins were smart millenia before we ever looked at their brains. The ancient Chinese knew it. Aristotle knew it. And the idea that brain size has anything to do with intelligence is, like, sooo 19th century.
Paul Manger from Johannesburg's University of the Witwatersrand,…
purepedantry | August 27, 2006I have talked before about evidence that there is no new neurogenesis in the adult cortex, but that paper used stereological techniques.
A new paper in PNAS shows a more direct method to demonstrate that there are no newly created neurons in the adult cortex -- and their technique for this is so clever that I have to talk about it. They use a spike in the atmospheric levels of Carbon 14 isotopes after nuclear testing -- before the Nuclear Test Ban Treaty of 1963 -- to carbon date the creation of new cells in the human brain.
First some background: If you want to start a fight among…