On Campus, the 1960s Begin to Fade as Liberal Professors Retire – NYTimes.com
Although the shift away from liberalism amongst faculty is interesting, this graphic caught my attention:
Should we take this to mean that there should be more faculty jobs as the avg age increases? (Or is this negated by the fact that people are living longer and working longer?)
Plants Found to Show Preferences for Their Relatives – NYTimes.com
Two amazing things here:
It refreshing to see this kind of interesting behavior without any neurons involved. It makes me think (realize) that the idea of a neuron or a neural system has many components and there might not be any good reason to assume that a single cell must have all of those properties or none of them. Something like a neuron-like cell that’s not a neuron in the classical sense. Anyone know of other examples?
Saw this on the Confocal list… Several times in the last few years I and others in the lab have debated the advantages and disadvantages of different fluorescence microscopy techniques. As many of you know, fluorescence microscopy is becoming increasingly important for many cool neuroscience techniques. But equally important in knowing how to properly image fluorescence.
Here’s a really thorough 2007 article from J. Microscopy that does a nice job of comparing wide-field/deconvolution, spinning disk confocal, and laser scanning confocal microscopy. Punchline is after the jump. (more…)
Fascinating. The first case of a person with virtually perfect autobiographic memory. In the interview, she says that she runs her entire life through her head every day. Perhaps the difference isn’t in memory capacity but rather the automatic (unconscious) practicing of all past sensory experience.
NPR interview with patient, John Gabrieli and Larry Cahill.
Link to paper. Abstract:
This report describes AJ, a woman whose remembering dominates her life. Her memory is “nonstop, uncontrollable, and automatic.” AJ spends an excessive amount of time recalling her personal past with considerable accuracy and reliability. If given a date, she can tell you what she was doing and what day of the week it fell on. She differs from other cases of superior memory who use practiced mnemonics to remember vast amounts of personally irrelevant information. We propose the name hyperthymestic syndrome, from the Greek word thymesis meaning remembering, and that AJ is the first reported case.
Salon has an interesting piece condemning a recent PBS show purportedly on Alzheimer’s treatment but really more of a sketchy informercial. The program concerns a neurologist with tenuous ties to UC Irvine who advocates SPECT (single photon emission computed tomograpy, a technique which, similar to PET, uses a radiotracer) and some unfounded preventative treatments for Alzheimer’s. The neurologist Bill Amen has appeared on many big-name media outlets including CNN, the Today Show, and Fox News (and the real sign of media success — Oprah) although his approach to Alzheimer’s detection and treatment is lacking in scientific credibility:
“SPECT scans are not sufficiently sensitive or specific to be useful in the diagnosis of A.D.,” neurologist Michael Greicius , who runs the Stanford University memory clinic, and has a special interest in the use of functional brain imaging in the diagnosis of A.D., tells me. “The PBS airing of Amen’s program provides a stamp of scientific validity to work which has no scientific validity.”
Continued pontification on neuroethics issues after the jump. (more…)
BioNumbers – The Database of Useful Biological Numbers
Here’s a neat new website. It’s a repository of quantitative information on biological things (eg. organisms, biomolecules, etc.) Some stuff I found while glancing through:
Number of mRNA/cell in E. coli: 138
Volume occupied by all RNA in E. coli: 6%
Average gene length in mammals: 16.6kb
Average gene length in nematode C. elegans: 4 kb
Mutation rate per genome per replication in humans: 0.16 mutation/genome/replication
Average time between blinks in humans: 2.8 sec
Amount of photons necessary to excite a cone in humans: 100
Citations are included for most numbers too. The database seems a little sparse on neuroscience topics, so go over and contribute some numbers!
If the Fish Liver Can’t Kill, Is It Really a Delicacy? [NYT, login]
Amazing. It looks like TTX (tetrodotoxin, a potent voltage-gated sodium channel blocker well-known to electrophysiologists) is not made by the pufferfish (which I had always assumed), rather it is from the bacteria/food consumed by the fish.
Decades earlier, another Japanese scientist had identified fugu’s poison as tetrodotoxin, a neurotoxin that leaves victims mentally aware while they suffer paralysis and, in the worst cases, die of heart failure or suffocation. There is no known antidote.
Researchers surmised that fugu probably got the toxin by eating other animals that carried tetrodotoxin-laden bacteria, developing immunity over time — though scientists then did not rule out the possibility that fugu produced the toxin on its own.
By this year, Mr. Noguchi had tested more than 7,000 fugu in seven prefectures in Japan that had been given only feed free of the tetrodotoxin-laden bacteria. Not one was poisonous.
“When it wasn’t known where fugu’s poison came from, the mystery made for better conversation,” Mr. Noguchi said. “So, in effect, we took the romance out of fugu.”
Aside from the interesting science, it appears there is also a small Japanese “industry” (de-ttx? detox?) seriously affected by TTX-free fugu. More after the jump (more…)
Full agenda is available here. Speakers are mostly a mix of neurotech CEOs and VCs (and Rep. Patrick Kennedy).
I’ve heard that there are no more free passes for students. (sadly) If anyone attends and would be willing to write-up something about the conference, please let me know and I’d be glad to put it on neurodudes.
The great Masao Ito, originator of one of the classic theories of cerebellar function, has published a new theory in the recent issue of Nature Neuroscience regarding how the cerebellum may be involved in control of cognition.
The basic idea is that while the cerebellum has evolutionarily had a role of refining motor commands for the purpose of controlling the skeleton, in the human the cerebellum is capable of refining commands from frontal cortex to “control” internal representations of the outside world. Ito uses the increasingly popular language of control theory to describe the effect that the cerebellum may have on different parts of the brain.
From the abstract:
The intricate neuronal circuitry of the cerebellum is thought to encode internal models that reproduce the dynamic properties of body parts. These models are essential for controlling the movement of these body parts: they allow the brain to precisely control the movement without the need for sensory feedback. It is thought that the cerebellum might also encode internal models that reproduce the essential properties of mental representations in the cerebral cortex. This hypothesis suggests a possible mechanism by which intuition and implicit thought might function and explains some of the symptoms that are exhibited by psychiatric patients. This article examines the conceptual bases and experimental evidence for this hypothesis.
An extremely interesting trend in neuroscience has been to use the language of Control Theory to explain brain function. A recent paper by Shadmehr and Krakauer does a very nice job of summarizing this trend and assembling a comprehensive theory of how the brain controls the body. Using control theory, they put forward a mathematically precise description of their theory. Because their theory uses blocks that are direct analogues of specific brain regions like the basal ganglia, motor cortex, and cerebellum, they can use brain lesion studies to undergird their ideas about these components. From the paper:
The theory explains that in order to make a movement, our brain needs to solve three kinds of problems: we need to be able to accurately predict the sensory consequences of our motor commands (this is called system identification), we need to combine these predictions with actual sensory feedback to form a belief about the state of our body and the world (called state estimation), and then given this belief about the state of our body and the world, we have to adjust the gains of the sensorimotor feedback loops so that our movements maximize some measure of performance (called optimal control).
At the heart of the approach is the idea that we make movements to achieve a rewarding state. This crucial description of why we are making a movement, i.e., the rewards we expect to get and the costs we expect to pay, determines how quickly we move, what trajectory we choose to execute, and how we will respond to sensory feedback.
This approach of describing brain lesion studies in the context of a well-thought out theory ought to be further encouraged.