As I’ve mentioned before, my class has been reading Time, Love, Memory: A Great Biologist and His Quest for the Origins of Behavior(amzn/b&n/abe/pwll), which is in large part an account of the amazing work Seymour Benzer accomplished over the course of his long career. Now I’ve got sad news to break to the students tomorrow: Seymour Benzer has died at the age of 86, after a long and exemplary career as a “scientist’s scientist”.
The seed of this mornings discussion in neurobiology was “Time, Love, Memory” by Jonathan Wiener. As has been the norm in past weeks we met in the on campus cafe bringing along with us four insightful questions each to keep the discussion rolling along throughout the hour. Wiener describes later in his book (p192) the three necessary components of living clocks. Living clocks are the basis of circadian rhythms and must have an input pathway so that the clock can be reset by the sunrise and sunset. A good example of why this is important is that humans actually have a twenty-five hour clock that resets itself everyday to correlate to the actual day length of twenty-four hours (23 hours, 56 minutes, and 4.1 seconds for any physicists reading this). People who are blind or people who are not exposed to the sun at all will exhibit a twenty-five hour clock, out of synchronization with the earth’s rotation.
So my question was about animals that live near the poles. How do polar bears or lynxes reset their clocks in the arctic summer when the sun doesn’t set? Some thoughts were that perhaps the living clocks are reset by magnetism but quickly realized that there is no shift of magnetism that corresponds to the length of a day. Another thought was that if it’s always light out, does it matter when the polar bear sleeps? The polar bear could have a period of activity, followed by a period of decreasing activity, and then rest and sleep. Lynxes often hunt at night and rest during the day but if it’s always light out does their clock remain synchronized with the earth’s rotation? PZ mentioned there isn’t much research pertaining to this but If anyone knows of any interesting papers that would enlighten this topic post them up.
References: Jonathan Wiener. “Time, Love, Memory.” Vintage Books, A Division of Random House, Inc. New York. 1999.
Researchers at Cambridge conducted a study that measured cognitive function and analyzed images of the brain in individuals with obsessive compulsive disorder (OCD). Magnetic resonance imaging (MRI) was used to capture images of each participants’ brain, and computerized tests were given to study the ability of the individual to stop repetitive behaviors. Also included in the study were healthy family members of the individuals with OCD, and healthy, unrelated individuals used as a control. The family members were included so that the genetic link behind OCD could be explored.
The researchers discovered that individuals with OCD and their relatives did worse on the computerized tasks than the healthy control group. When the MRI photos were analyzed, individuals with OCD and their relatives were found to have distinct patterns in their brain structure, namely a decrease in grey matter in brain regions associated with the suppression of responses and habits.
It was noted that this decrease in grey matter may contribute to the characteristic compulsive and repetitive behaviors associated with OCD. However, researchers are still a long way from discovering the genes involved with OCD, and further research needs to be done to explore why some family members with the altered brain structure do not develop OCD.
Since the family members have similar brain structure, there must be something else contributing to the development of OCD. I wonder if there is something going on inside that is causing a chemical imbalance that contributes to OCD, or if environmental factors are important in the development of OCD. It would be interesting to look at identical twins and see what the pattern of OCD is in them.
This is why we need to keep a few philosophers around: they can succinctly name the logical fallacies committed by a certain cosmologist.
I once overheard an interesting confession from a friend of a friend. This guy had been drinking and was admitting to his buddy that he just wanted to get into a fight, punch the next person that walked through the door, stir things up. That sort of thing. I complained to my companion that it was precisely this attitude that causes so much conflict in society and, though my friend agreed, he sheepishly added that sometimes he too enjoyed the thrill of physical violence.
I was reminded of the incident recently in a class on the origins of aggression when we read a passage from Journalist Bill Buford’s Among the Thugs. Buford spent eight years documenting violent episodes in sports crowds and riots. He wrote of the intensity of a violent experience:
I am attracted to the moment when consciousness ceases: the moments of survival, of animal intensity, of violence, when there is no multiplicity, no potential for different levels of thought: there is only one–the present in its absoluteness
If we really can find a sort of solace, release, or even satisfaction in violence, I think this says something about our race, and it makes me wonder if peace is really attainable. We may find it difficult to identify with violent people as we are now, but how would we react if a loved one were taken from us? Would we want revenge? Maybe revenge is the search for the relief that violence can bring however transient or ultimately tragic.
Check out Deltoid for a set of refutations of common global warming denialist arguments. Then you can whine on that blog. (this thread is at 1146 comments right now—I think the blog is full, time to move on.)
As I wrote about before, my semester lab project for neurobiology has to do with regeneration. The idea is to damage the spinal cord and observe wonderful regeneration. This proposal was based on some articles I read about regeneration of zebrafish hearts, fins, tails, etc. Unfortunately I haven’t had much luck so far.
Last week, armed with an exacto knife, I performed my first round of spinal cord butchering on fifteen zebrafish that were only a few days old. The zebrafish are captured with a glass pipet and then immobilized using auger that’s just warm enough to be in liquid phase. They are then mounted on a slide under the stereoscope. I quickly discovered many faults in my methods, one of which being that I captured the fish in too many drops of water so when the auger was added in a test tube, the fish weren’t completely immobilized. I would then carefully approach a fish with the exacto knife on the slide under the scope and it would turn into a bucking bronco. Eventually I perfected the art of capturing the few day old zebrafish with the pipet and putting them in test tubes in only one drop of water, thus partially solving the immobilization issue.
The second problem I encountered is that there is nothing exact about an exacto knife under a stereoscope. Accomplishing this spinal cord severing is much like peeling an orange with a baseball bat in that it’s extremely difficult without making a mess. Even with the fish immobilized the tail doesn’t really stay put when pressure is applied with the seemingly crowbar sized exacto knife. The key to this dilemma, although I have yet to master it, is probably making the layer of auger on the slide as thin as humanly possible so that there isn’t as much room for movement.
All the zebrafish from my first attempt died. Two of them were alive for a day or so but barely. I did another round of zebrafish butchering with fifteen more fish yesterday (yes I enjoy spending my Sunday afternoon in the neurolab) and from what I could tell, all but two of them died immediately. I’ll have to see if the elite two are still swimming around today but if not, I’ll try yet another round of fifteen and see how it goes. If anyone has any ideas for instruments or methods that could improve my success, feel free to insert a comment.
In preparation for my trip to the Caribbean next semester, I spent this weekend taking a class to learn how to SCUBA dive. My class and I learned all about the necessary equipment, what to do in emergency situations, and how to stay safe while SCUBA diving. We also learned about the physics of pressure, volume and density, so that we could better understand what happens when you descend into the deep. This inevitably led to a conversation about Nitrogen narcosis.
Nitrogen narcosis, or “rapture of the deep”, is a condition in which the symptoms resemble those due to intoxication by alcohol. Divers experiencing nitrogen narcosis lose their decision making abilities, their focus, and their judgment, coordination and multitasking skills become impaired. What could this potentially mean for the diver? They could ignore safe diving practices because they feel invulnerable to the dangers of their surrounding environment (sounds a bit like the actions of those individuals who are intoxicated by alcohol).
Synesthesia is going to be the discussion topic for our upcoming neuroslam in two weeks. Synesthesia is the rare ability of a select few individuals to see numbers as colors or as in the article that I’m preparing to discuss (Hubbard 1996), experience varying degrees of light and dark as melodic intervals. The observed pattern is that individuals experience lower pitches or descending melodic intervals in correlation with darker stimuli and higher pitches or ascending melodic intervals in correlation with lighter stimuli. The important detail about synesthesia is that individuals experience it involuntarily whereas most individuals without synesthesia can choose to consider a set of stimuli using a secondary sense that they normally wouldn’t.
One of the experiments discussed in this article was conducted with undergraduate students coaxed into participating with the offer of some credit for an intro to psychology course. The students were placed in front of an Apple RGB color monitor and grey squares of differing light intensities were presented in conjunction with a perfect fifth for four seconds. Eight perfect fifths were used, each beginning on a different tonic and thus each having a unique frequency. The squares were presented on either a white or black background. The students then rated how similar the square and the interval were on a scale with one as the least and nine as the most. One of the questions considered with this experiment is the effect of contrast between the background and the grey squares on perception.
A second experiment was set up similar to the first experiment except that students (who had not participated in the first experiment) were presented with an interval at one of the selected frequencies and asked to choose among several light intensities of grey which correlated best. Correlating one perfect fifth to a light intensity that was presented with multiple light intensity options successfully diminished (no pun intended) the effects of background contrast on perception.
I thought of some questions when I was reading this article and then afterward studying for music theory. Are there individuals who experience synesthesia such that they correlate varying degrees and intensities of lightness with more complex types of music intervals? Do minor or diminished intervals correlate to a different light intensity than major or augmented intervals? What about different intervals of the same quality? Do ascending minor sixths correlate to a different light intensity than ascending minor thirds? If an individual with true synesthesia enters a concert hall do they experience sensory overload? (just kidding) I’m sure one of us neurobio students will post about neuroslam in a couple weeks to fill everyone in on our discussions but until then there is a lot of good reading on the subject.
References:
Timothy L. Hubbard. “Synesthesia-like mappings of lighness, pitch, and melodic interval.” American Journal of Psychology. 1996. v109n2: p219
It’s puzzling: he’s a rich and successful engineer, but I don’t see any particular virtue to his participation at SfN, and judging by these remarks, he just exposed himself for an ignoramus.
During the time Andrew S. Grove spent at Intel, the computer chip company he co-founded, the number of transistors on a chip went from about 1,000 to almost 10 billion. Over that same period, the standard treatment for Parkinson’s disease went from L-dopa to … L-dopa.
Grove (who beat prostate cancer 12 years ago and now suffers from Parkinson’s) thinks there is something deeply wrong with this picture, and he is letting the pharmaceutical industry, the National Institutes of Health and academic biomedicine have it. Like an increasing number of critics who are fed up with biomedical research that lets paralyzed rats (but not people) walk again, that cures mouse (but not human) cancer and that lifts the fog of the rodent version of Alzheimer’s but not people’s, he is taking aim at what more and more critics see as a broken system.
The institution of research in this country isn’t without its flaws, but Grove doesn’t have a clue. There are two big reasons we can’t just ramp up biomedical research and see new results flowing out of the pipeline and into the hospitals at an accelerated rate. The biological research program is not comparable to Intel’s computer chip production!
Biological research is not an exercise in applied engineering — we’re trying to discover fundamental unknown elements of biology, and it isn’t at all like scaling up or refining chip production. This is important: you can’t make science a process of applied engineering without destroying it. The job of the scientist is to uncover whole new principles and concepts, and that means there is a lot of scurrying about to reveal stuff that isn’t immediately obvious how it can be used in a practical sense.
Grove is looking in the wrong places. We’re seeing rapid progress in many fields of science — evo-devo, to name one close to my heart — and he’s simply blind to them, and demanding immediate productivity in areas where he can’t even define the problem and which need more basic research to improve our understanding.
I would be more impressed with the superiority of engineering in the L-dopa example of Grove’s strategy for improving a chip didn’t involve throwing out the old model and plugging in a new one. Why didn’t Intel develop a treatment for my old 8088 that would transform it into a quad-core 64-bit Xeon. One could argue, I suppose, that our comparable strategy for Parkinson’s is to allow the old relics to die off while our Uterine Fab Units build brand new brains that work without crashing.
It’s especially ironic since he is demanding new treatments because he has Parkinson’s, and now he thinks he can just demand a cure on a schedule, like he was ordering an iPhone.
It’s too bad Grove wasted all those years playing with simple toys like microprocessors instead of trying to understand something rather more complex.
