Category Archives: Neuroscience

Train your Brain

Over the past several months, Alvaro of SharpBrains blog interviewed eleven neuroscientists on the topic of the ability to use various techniques to affect the way our brains function – brain training. He has now put together a collection of key quotes from the eleven interviews, each quote linking to the interview itself. Interesting reading on the cutting edge of neuroscience.

Evolution of Adoption

If we are not there at the moment of birth, how come we can bond with the baby and be good fathers or good adoptive parents? Kate explains. Obligatory Reading of the Day.
Update: Related is this new article by former Scibling David Dobbs: The Hormone That Helps You Read Minds
Update 2: Matt responds to Kate’s post.
Update 3: Kate wrote a follow-up: Why help out? The life of an alloparent

Who is Eva Vertes?

I have linked to and posted pictures of Eva Vertes from SciFoo before and you may ask: “Who is she? Why was she invited there?” The Wikipedia page I linked to earlier is a short stub and full of errors. So, to make it clear, see this page as well as comments on this talk she gave two years ago when she was 17:

Neuroethology in Vancouver

Bjoern Brembs is at the ICN meeting and is blogging about the talks he saw. If I went, I would have probably attended a completely different set of talks, e.g., on birdsong, memory in food-caching birds, aggression in crustaceans, strange sensory systems, spatial orientation and animal cognition, but I am certainly glad that Bjoern has highlighted the best of what he saw there:
Robert de Ruyter van Steveninck: Velocity estimation and natural visual input signals
Martin Egelhaaf: Active vision: a strategy of complexity reduction in behavioral control
Roy Ritzmann: Movement through complex terrains by insects and robots
Jack Gray: Complex behavior from compact systems
Leslie Griffith: Sex and the single fly: Pheromone-mediated learning
Sarah Dunlop: Recovery of function after CNS and PNS injury
Leslie Vosshall: Molecular neuroethology of olfaction in Drosophila
Claude Desplan: The color vision circuitry in Drosophila
Jan Ramirez: The neuronal basis of inspiration
Piali Sengupta: Running hot and cold: Thermosensory behaviors in C. elegans

Are you physically addicted to Harry Potter?

It is certainly possible. Compared to some people I know, I am definitely not. I have read each of the books once (more than halfway through the 7th – so do not give me spoilers yet!) and I have seen each of the movies once. I enjoy them, but do nothing on top of it: no speculations, no obsessions, no additional activity.

The hole in your head!

Mo is really spoiling us with exciting, well-researched posts from the history of science and medicine (remember the trepination post from a month ago?). And here he does it again: The rise & fall of the prefrontal lobotomy, the most gripping post on science blogs this week. And a Wicked Stepmother is one of the main characters!

Brain and Mind articles

Our former scibling David Dobbs has posted/published two interesting articles about recent findings in neuroscience and behavior:
The Gregarious Brain in New York Times Magazine, about the Williams Syndrome:

If a person suffers the small genetic accident that creates Williams syndrome, he’ll live with not only some fairly conventional cognitive deficits, like trouble with space and numbers, but also a strange set of traits that researchers call the Williams social phenotype or, less formally, the “Williams personality”: a love of company and conversation combined, often awkwardly, with a poor understanding of social dynamics and a lack of social inhibition. The combination creates some memorable encounters.

It’s just your imagination — Or is it your memory? on the SciAm blog:

As we explored in the very first Mind Matters post, neuroscientists everywhere agree that the hippocampus is crucial to memory — but have rich and interesting disagreements about how this brain area creates and manages memory and what roles it might play in cognition. This debate was freshly enlivened in early 2007 when an innovative paper by Demis Hassabis (a former chess prodigy and games designer) and colleagues at the renowned University College London lab of Eleanor Maguire proposed that the hippocampus is vital not just for memory but also for imagination. As hippocampal researcher Andre Fenton notes in his review below, this discovery suggests both a vital new role for the hippocampus and a narrative-building mechanism common to memory, imagination, and thought. Interesting new ground, Fenton finds, but not without its hazards.

A worm with an ur-hypothalamus?

Modern Brains Have An Ancient Core:

Hormones control growth, metabolism, reproduction and many other important biological processes. In humans, and all other vertebrates, the chemical signals are produced by specialised brain centres such as the hypothalamus and secreted into the blood stream that distributes them around the body.
Researchers from the European Molecular Biology Laboratory [EMBL] now reveal that the hypothalamus and its hormones are not purely vertebrate inventions, but have their evolutionary roots in marine, worm-like ancestors. In this week’s issue of the journal Cell they report that hormone-secreting brain centres are much older than expected and likely evolved from multifunctional cells of the last common ancestor of vertebrates, flies and worms.
———snip————–
Scientist Kristin Tessmar-Raible from Arendt’s lab directly compared two types of hormone-secreting nerve cells of zebrafish, a vertebrate, and the annelid worm Platynereis dumerilii, and found some stunning similarities. Not only were both cell types located at the same positions in the developing brains of the two species, but they also looked similar and shared the same molecular makeup. One of these cell types secretes vasotocin, a hormone controlling reproduction and water balance of the body, the other secretes a hormone called RF-amide.
Each cell type has a unique molecular fingerprint – a combination of regulatory genes that are active in a cell and give it its identity. The similarities between the fingerprints of vasotocin and RF-amide-secreting cells in zebrafish and Platynereis are so big that they are difficult to explain by coincidence. Instead they indicate a common evolutionary origin of the cells. “It is likely that they existed already in Urbilateria, the last common ancestors of vertebrates, insects and worms” explains Arendt.
Both of the cell types studied in Platynereis and fish are multifunctional: they secrete hormones and at the same time have sensory properties. The vasotocin-secreting cells contain a light-sensitive pigment, while RF-amide appears to be secreted in response to certain chemicals. The EMBL scientists now assume that such multifunctional sensory neurons are among the most ancient neuron types. Their role was likely to directly convey sensory cues from the ancient marine environment to changes in the animal’s body. Over time these autonomous cells might have clustered together and specialised forming complex brain centres like the vertebrate hypothalamus.
———-snip—————

“The vasotocin-secreting cells contain a light-sensitive pigment”? Why? Any connections to the mammalian SCN secreting vasopresin?

Look! There’s a hole in your head!

The history of trepanation. An utterly amazing post!
And, Bioephemera posted an appropriate illustration to go with it….

Gastropod Neuroscience

Bjoern Brembs is attending and liveblogging from the Gastropod Neuroscience meeting at Friday Harbor Laboratories and has posted about several talks already and will likely post more over the next couple of days.
Something struck me in his coverage of Dennis Willows’ talk about magnetoreception in Tritonia:

However, in 20 years of research, the researchers haven’t found the cells which sense the magnetic field and transmit the information to the neurons in the brain.

Well, Ken Lohmann, barely a mile or so from me, has already published several papers on Tritonia neurons sensitive to changes in the Earth’s geomagnetic field. Is there a controversy about this? I doubt Willows is unaware of Lohmann’s work, so why did he ignore it in his talk? Or did I misunderstand that remark?
Ronald Chase: snails slugs and sex adds more complexity to the story of penis fencing in molluscs than I was aware of previously.
More from the meeting so far:
Robert Meech: Why Mollusks behave the way they do
Richard Satterlie: Swimming Speed Changes in a Predatory Mollusk
Leonard Kaczmarek: Regulation of prolonged changes in neuronal excitability
Klaude Weiss: Dynamic reorganization of the feeding CPG of Aplysia (Aplysia used to be a biggie animal model in circadian field, but I don’t think there is anyone working on it any more)
Paul Katz: Nudibranchs, Neuromodulation, Neural circuits, & Neuromics
Unfortunately, no pretty pictures of Nudibranchs (or any gastropods for that matter – just people, people, people). For that, you have to visit Bouphonia on Fridays.

Flirting under Moonlight on a Hot Summer Night, or, The Secret Night-Life of Fruitflies

Blogging on Peer-Reviewed Research

As we mentioned just the other day, studying animal behavior is tough as “animals do whatever they darned please“. Thus, making sure that everything is controlled for in an experimental setup is of paramount importance. Furthermore, for the studies to be replicable in other labs, it is always a good idea for experimental setups to be standardized. Even that is often not enough. I do not have access to Science but you may all recall a paper from several years ago in which two labs tried to simultaneously perform exactly the same experiment in mice, using all the standard equipment, exactly the same protocols, the same strain bought from the same supplier on the same date, the same mouse-feed, perhaps even the same colors of technicians’ uniforms and yet, they got some very different data!
The circadian behavior is, fortunately, not chaotic, but quite predictable, robust and easily replicable between labs in a number of standard model organisms. Part of the success of the Drosophila research program in chronobiology comes from the fact that for decades all the labs used exactly the same experimental apparatus, this one, produced by Trikinetics (Waltham, Massachusetts) and Carolina Biologicals (Burlington, North Carolina):
drosophila%20apparatus.jpg
This is a series of glass tubes, each containing a single insect. An infrared beam crosses the middle of each tube and each time the fly breaks the beam, by walking or flying up and down the tube, the computer registers one “pen deflection”. All of those are subsequently put together into a form of an actograph, which is the standard format for the visual presentation of chronobiological data, which can be further statistically analyzed.
The early fruitfly work was done mainly in Drosophila pseudoobscura. Most of the subsequent work on fruitfly genetics used D.melanogaster instead. Recently, some researchers started using the same setup to do comparative studies of other Drosophila species. Many fruitfly clock labs have hundreds, even thousands, of such setups, each contained inside a “black box” which is essentially an environmental chamber in which the temperature and pressure are kept constant, noise is kept low and constant (“white noise”), and the lights are carefully controlled – exact timing of lights-on and lights-off as well as the light intensity and spectrum.
In such a setup, with a square-wave profile of light (abrupt on and off switches), every decent D.melanogaster in the world shows this kind of activity profile:
fruitfly%20crepuscular.JPG
The activity is bimodal: there is a morning peak (thought to be associated with foraging in the wild) and an evening peak (thought to be associated with courtship and mating in the wild).
The importance of standardization is difficult to overemphasize – without it we would not be able to detect many of the subtler mutants, and all the data would be considered less trustworthy. Yet, there is something about standardization that is a negative – it is highly artificial. By controlling absolutely everything and making the setup as simple as possible, it becomes very un-representative of the natural environment of the animal. Thus, the measured behavior is also likely to be quite un-natural.
Unlike in the lab, the fruitflies out in nature do not live alone – they congregate with other members of the species. Unlike in a ‘black box’, the temperature fluctuates during the day and night in the real world. Also unlike the lab, the intensity and spectrum of light change gradually during the duration of the day while the nights are not pitch-black: there are stars and the Moon providing some low-level illumination as well. Thus, after decades of standardized work, it is ripe time to start investigating how the recorded behaviors match up with the reality of natural behavior in fruitflies.
Three recent papers address these questions by modifying the experimental conditions in one way or another, introducing additional environmental cues that are usually missing in the standard apparatus (and if you want to know what they found, follow me under the fold):

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And now the scientists will do whatever they damned please (start shouting, most likely)

Google was really no help in finding the exact quote, but everyone in the animal behavior field has heard some version of the Harvard Rule of Animal Behaviour:

“You can have the most beautifully designed experiment with the most carefully controlled variables, and the animal will do what it damn well pleases.”

Anyone here knows who actually said that and what were the exact words?
Anyway, one way to re-word the “whatever they damned please” is to call it “free will”. Björn Brembs says so but apparently not everyone agrees. The discussion in the media and on blogs is just about to start because Bjorn’s paper about spontaneous behavior in Drosophila just came out today (after quite a long wait). You can read the summary by Bjorn, but I also suggest you try to read the actual paper. If seemingly spontaneous behavior can be described by mathematical formulas, even if it is chaotic dynamics, is it then, really, quite deterministic? If so (or if not) can it be called “free will”? If not, is there a better term for it?
Keep an eye on the discussion on Bjorn’s blog as well as the discussion attached to the PLoS-ONE paper itself and, if you have read and understood the paper, please contribute to the discussion. This is bound to get very interesting over the next several days.

My Picks From ScienceDaily (Neuro edition)

Lots of interesting Neuro/Behavioral stuff came out lately, some really cool, some questionable…so you let me know what you think:
Brain’s White Matter: More ‘Talkative’ Than Once Thought:

Johns Hopkins scientists have discovered to their surprise that nerves in the mammalian brain’s white matter do more than just ferry information between different brain regions, but in fact process information the way gray matter cells do. The discovery in mouse cells, outlined in the March issue of Nature Neuroscience, shows that brain cells “talk” with each other in more ways than previously thought. “We were surprised to see these nerve axons talking to other cells in the white matter,” says Dwight Bergles, Ph.D., an associate professor of neuroscience at Hopkins.

Traumas Like Sept. 11 Make Brains More Reactive To Fear:

According to a new brain study, even people who seemed resilient but were close to the World Trade Center when the twin towers toppled on Sept. 11, 2001, have brains that are more reactive to emotional stimuli than those who were more than 200 miles away.

Newborn Neurons Like To Hang With The ‘In’ Crowd:

Like any new kid on the block that tries to fit in, newborn brain cells need to find their place within the existing network of neurons. The newcomers jump right into the fray and preferentially reach out to mature brain cells that are already well connected within the established circuitry, report scientists at the Salk Institute for Biological Studies in the online edition of Nature Neuroscience.

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Conception Date Affects Baby’s Future Academic Achievement (!?)

It could be the seasonal use of pesticides, as this study suggests, or it could be seasonality in nutrition of mothers and infants, or seasonality of environmental stressors, or seasonality of mothers’ hormone profiles. Most likely all or most of these and other factors play a role, and the relative importance of the factors differs between geographic regions, between socioeconomic strata, and between times in history.
But there is one factor that has been repeatedly demonstrated to play no role at all: the position of planets, moons and stars, as seen from Earth, at the moment of birth of a baby….

But do they stop to ask for directions?

Sex And Prenatal Hormone Exposure Affect Cognitive Performance:

Yerkes researchers are using their findings to better understand sex differences in cognitive performance, which may lead to increased understanding of the difference in neuropsychological disorders men and women experience.
In one of the first research studies to assess sex differences in cognitive performance in nonhuman primates, researchers at the Yerkes National Primate Research Center have found the tendency to use landmarks for navigation is typical only of females.
This finding, which corroborates findings in rodents and humans and is available in the online edition of Hormones and Behavior, suggests there is not just a difference in how well females and males solve spatial problems, but also in which types of cues they use to solve such problems. Researchers are applying this knowledge to gain a better understanding of how the brain develops and functions.

The Third Brain Should Have Its Own Clock

I have written about the relationship between circadian clocks and food numerous times (e.g., here, here and here). Feeding times affect the clock. Clock is related to hunger and obesity. Many intestinal peptides affect the clock as well.
There is a lot of research on food-entrainable oscillators, but almost nothing on the possibility that there is a separate circadian pacemaker in the intestine. It is usually treated as a peripheral clock, entirely under the influence of the SCN pacemaker in the brain, even when it shows oscillations in clock-gene expression for several days in a dish.
But why not have a true pacemaker in the gut? The intestinal nervous system is large and semi-autonomous. It makes sense that there would be a circadian clock in there. After all, all the GI functions follow daily rhythms.
I remember that there was a paper – a VERY old paper – that showed that an isolated intestine in a dish shows circadian rhythms of motility. I could not locate that paper. If you can, please let me know.

A potential animal model for Bipolar Disorder

It has been known for quite a while now that bipolar disorder is essentially a circadian clock disorder. However, there was a problem in that there was no known animal model for the bipolar disorder.
Apparently that has changed, if this report is to be believed:

“There’s evidence suggesting that circadian genes may be involved in bipolar disorder,” said Dr. Colleen McClung, assistant professor of psychiatry and the study’s senior author. “What we’ve done is taken earlier findings a step further by engineering a mutant mouse model displaying an overall profile that is strikingly similar to human mania, which will give us the opportunity to study why people develop mania or bipolar disorder and how they can be treated.”

Wow! This is radical!

Every time someone proposes a radical rewriting of science textbooks, one needs to proceed with caution. There is so much evidence for electrical potentials in nerve cells, this sounds really fishy:
Action Of Nerves Is Based On Sound Pulses, Anesthetics Research Shows:

Nerves are ‘wrapped’ in a membrane composed of lipids and proteins. According to the traditional explanation of molecular biology, a pulse is sent from one end of the nerve to the other with the help of electrically charged salts that pass through ion channels in the membrane. It has taken many years to understand this complicated process, and a number of the scientists involved in the task have been awarded the Nobel Prize for their efforts. But — according to the physicists — the fact that the nerve pulse does not produce heat contradicts the molecular biological theory of an electrical impulse produced by chemical processes. Instead, nerve pulses can be explained much more simply as a mechanical pulse according to the two physicists. And such a pulse could be sound. Normally, sound propagates as a wave that spreads out and becomes weaker and weaker. If, however, the medium in which the sound propagates has the right properties, it is possible to create localized sound pulses, known as “solitons”, which propagate without spreading and without changing their shape or losing their strength.

So, why have ion channels in the first place? What are the Nodes of Ranvier for? Why invertebrates, who do not have myelin, increase the speed of tranmission by making the axon diameter larger?
Color me sceptical for now….

Physiology: Regulation and Control

Physiology: Regulation and Control
The penultimate installment of lecture notes in the BIO101 series. Help me make it better – point out errors of fact and suggest improvements:

Continue reading

New Model for Interval Timing

While study of Time-Perception is, according to many, a sub-discipline of chronobiology, I personally know very little about it. Time perception is defined as interval timing, i.e., measuring duration of events (as opposed to counting, figuring which one of the two events happened first and which one second, or measuring time of day or year).
Still, since this blog is about all aspects of biological timing, I have to point you to a new paper in Neuron (press release) about a new computer model for human time-perception.

“If you toss a pebble into a lake,” he explained, “the ripples of water produced by the pebble’s impact act like a signature of the pebble’s entry time. The farther the ripples travel the more time has passed.
“We propose that a similar process takes place in the brain that allows it to track time,” he added. “Every time the brain processes a sensory event, such as a sound or flash of light, it triggers a cascade of reactions between brain cells and their connections. Each reaction leaves a signature that enables the brain-cell network to encode time.”

Of course, this is a little vague as far as neurophysiology goes, and we need to remember that even the most brilliant mathematical model may end up being wrong. Still, the model seems nifty and I hope they follow up with real lab work to test it.
Steve of Omni Brain has more and points to this 2005 review of the topic in Nature Review Neuroscience.

Friday Weird Sex Blogging – Sensory Neuroscience

In a time-crunch like this, one can always count on Buzz Skyline to save the day…..

NeuroBlogging of the week

Encephalon #13 is up on Neurotopia. Lots of great stuff!

CO2 Receptors in Insects

Identification Of Carbon Dioxide Receptors In Insects May Help Fight Infectious Disease:

Mosquitoes don’t mind morning breath. They use the carbon dioxide people exhale as a way to identify a potential food source. But when they bite, they can pass on a number of dangerous infectious diseases, such as malaria, yellow fever, and West Nile encephalitis. Now, reporting in today’s advance online publication in Nature, Leslie Vosshall’s laboratory at Rockefeller University has identified the two molecular receptors in fruit flies that help these insects detect carbon dioxide. The findings could prove to be important against the fight against global infectious disease.

This is a very important finding. For context of the importance of CO2 in transmission of malaria, check out this.

The Science Of Driving And Traffic – the importance of breaking the rules

Let me state up front that this is not a topic I know anything about, but I have always had a curiosity for it, so let me just throw some thoughts out into the Internets and see if commenters or other bloggers can enlighten me or point me to the most informative sources on the topic. This is really a smorgarsbord of seemingly disparate topics that I always felt had more in common with each other than just the fact that they have something or other to do with traffic. I am trying to put those things together and I hope you can help me (under the fold).

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NeuroBlogging of the week

The Synapse #13 is up on Neurocontrarian. Go take a look.
This will be the last edition of The Synapse. The two neuro-carnivals are going to fuse into one, so in the future, only submit your entries to Encephalon.

NeuroBlogging of the week

The Synapse #12 is up on Dr. Deborah Serani’s blog

NeuroBlogging of the week

Encephalon #11 is up on The Mouse Trap.

NeuroBlogging of the week

The Synapse #11 is up on Developing Intelligence. As expected, I am most excited about this post on Mouse Trap.

Retinal cell transplantation restores photoreception

Cell transplant for eyes?

In the current study, the scientists looked at these photoreceptors’ development — from the embryonic stages to those in the newborn. They found that the cells that worked best came from animals between the first and fifth days of life. “Photoreceptors are just being born and starting to make connections,” said Pearson, one of the co-authors of the study, published this week in Nature.
The retinal cells were transplanted in normal adult mice and others with two different types of vision problems that cause blindness. In earlier studies, researchers found that the cells looked like photoreceptors and seemed to act like them. But the real test was laid out in this current study.
Ten mice who received the retinal transplants were studied to see whether there were functional changes. When a light was shone in the retina, electrical signals came out of the cells, suggesting that the animals were responding to a light that under normal situations they would not have seen. Scientists also observed the pupils constricting in the mice, another sign they were registering the light in their eyes and the message was traveling to the brain.
“We restored some aspects of visual function,” Pearson said. “But we have no idea yet what the animals can or can’t see. It’s still a long way off from a human treatment.”

So, photoreception was restored, but vision probably was not. I am wondering if a cell transplant of retinal ganglion cells mat restore circadian photoreception – a serious problem in some blind people who “freerun” instead of being synchronized to the day-night cycle.

ENCEPHALON

Welcome to the 10th edition of the Encephalon, the blog carnival of brains, minds, neurons, behavior and cognition. This was a busy week (and weekend) for me, so I decided to give up on the spectacularly difficult idea I had for creative hosting and go with a traditional style. After all, it is the contributors’ posts that you came here to find, not my artistic aspirations. So, let’s get right into it!
Coffee Mug, one of the bloggers on the original Gene Expression won the contest (by solving the neurotransmitter puzzle) last time I hosted The Synapse and the prize is – being highlighted first today. So, here is his contribution, Place and Plasticity: Two Views on the Hippocampus, the post you have to read first of all.
Alvaro of SharpBrains submitted three entries this week: Neurogenesis and How Learning Saves Your Neurons, Cognitive Neuroscience and ADD/ADHD Today and Cognitive Simulations for Basketball Game-Intelligence: Interview with Prof. Daniel Gopher,.
Sandy G of The Mouse Trap sent a two-part post regarding how a new kind of stroop test may help us resolve questions regarding language specificity vs domain general modesl of language: Color memory, stroop test and models of working memory and Incongruence perception and linguistic specificity: a case for a non-verbal stroop test.
The neurophilosopher from the The Neurophilosopher’ weblog, the founder of this carnival, also sent two entries: 100 years of Alzheimer’s Disease and Navigation neurons put monkeys on the right track.
Mary of The Thinking Meat Project gives us these two: Neurons linked to social behavior and To see ourselves as others see us.
Michael of Peripersonal Space has two posts very closely related to the title of his blog: Hands, tools, neglect and the parietal lobe and The long arm experiment.
From RDoctor comes Multiple Sclerosis. Quiz:.
I saw these two posts on The Neurocritic that I could not resist including in here as Editor’s Choices: Invisible Nudes Redux and Glossolalia.
From AlphaPsy, a group blog, two posts by Olivier – The Blushing Brain and Peculiar Tastes – and one by Hugo: Who thinks the Earth is flat?
Now for a medley of picks from the Seed Magazine’s sciencebloggers’ blogs:
From Dave and Greta Munger of Cognitive Daily: Face recognition: Not just about processing speed and Don’t let your kids read this entry (Chocolate doesn’t make them hyper).
From Chris of Mixing Memory: Motivated Seeing? Motivation Affects Visual Perception and A Unified Psychology?
From Shelley Batts of Retrospectacle: Will Longer Life Leave Us All Demented? and Debunking the Myth of the Non-Echoing Duck Quack/
From Jake Young of Pure Pedantry: Janet Hyde and Marcia Linn on the Psychological Similarity between Men and Women
From Jonah Lehrer of The Frontal Cortex: The Moral Mind and Basketball Players and The Hot Hand.
From Joseph of Corpus Callosum: Effect of Night-Shift Nap on ER Residents and Nurses and General’s Advice: US Needs Sexual Literacy.
From me: Development of the human sleep patterns.
And let’s finish with some fun! From Sandra Porter of Discovering Biology in a Digital World: a three-part Halloween story: Tales From The Lab, part I, part II and finale.
Next week, it’s time for The Synapse again, and in two weeks, Encephalon comes back at The Mouse Trap.

Encephalon – last call for submissions

This is the last reminder to send me permalinks to your recent posts related to neurons, brains, behavior and cognition for the next edition of Encephalon, the neuroscience carnival. I need them by midnight today. I’ll post the carnival tomorrow morning.
Send the links to:
encephalon.host AT gmail DOT com
or
Coturnix AT gmail DOT com

Neuroblogging of the week

The Synapse #10 is up on Neurocritic. Next week, it is the turn for Encephalon (the two neurocarnivals appear on alternate weeks) and it will be hosted by me, right here. Send your entries by November 5th at 5pm EST to: Coturnix AT gmail DOT com.

Brain Blogging of the week

Encephalon #9 is up on Migrations. The next edition will be here on November 6th. Send your entries to: Coturnix AT gmail DOT com

No all-nighters for you!

Shelley went to the Society for Neuroscience meeting and saw a talk on sleep deprivation, memory and hippocampus.

The Synapse

The Synapse #9 – the special Society for Neuroscience Edition is up on Pure Pedantry

Encephalon #7

The brand new edition of Encephalon is up on Cognitive Daily. Could you be accepted to attend Encephalon University?

Easy On The Eyes

Beauty And The Brain:

Experiments led by Piotr Winkielman, of the University of California, San Diego, and published in the current issue of Psychological Science, suggest that judgments of attractiveness depend on mental processing ease, or being “easy on the mind.”
“What you like is a function of what your mind has been trained on,” Winkielman said. “A stimulus becomes attractive if it falls into the average of what you’ve seen and is therefore simple for your brain to process. In our experiments, we show that we can make an arbitrary pattern likeable just by preparing the mind to recognize it quickly.”

Read the whole thing and comment.

BrainBlogging of the week

Encephalon #7 is up on Omni Brain

MRI getting smaller (and cheaper)

It’s looking good. Certainly much smaller than the roomful of metal we are used to seeing in hospitals.
Do you remember when computers used to fill entire rooms? Now take a look at your cell phone. Now think MRI in 10-20 years…
See what I’m getting at?
I am patiently waiting for the time when MRIs are small and light enough to be mounted on heads of freely behaving animals (in the wild or in captivity), at least large animals like elephants, dolphins, horses, crocs or sharks… Then you use radiotelemetry to get the info loaded on your computer and you observe the brain activity in real time as the animal is interacting with its environment.
I hope this happens while I am still young and active enough to use such technology in research…

Nicotine and Depression

Nicotine Lessens Symptoms Of Depression In Nonsmokers:

Nicotine may improve the symptoms of depression in people who do not smoke, Duke University Medical Center scientists have discovered.
The finding does not mean that people with depression should smoke or even start using a nicotine patch, the researchers caution. They say that smoking remains the No. 1 preventable cause of death and disability in the United States, and that the addictive hazards of tobacco far outweigh the potential benefits of nicotine in depression.
But the finding suggests that it may be possible to manipulate nicotine’s effects to safely reap its potential medical benefits, according to the researchers. As an example of the drug’s potential, they said, pharmaceutical companies already are developing compounds for treating other brain disorders by mimicking the beneficial properties of nicotine while avoiding its addictive nature.
———————–snip———————
“Our study also provides evidence that smokers may indeed smoke, in part, to improve their mood — a notion that has been quite controversial in the field,” he said.
————————snip———————-
Scientists have established that people prone to depression are twice as likely to be smokers, and are less likely to succeed in quitting smoking after taking up the habit, according to McClernon. The Duke study explored the theories behind the higher smoking rates among people experiencing depression.
“Smokers may be more prone to depression than nonsmokers,” said Edward Levin, Ph.D., a professor of biological psychiatry and researcher at the Duke center, who was senior investigator in the current study. “Or, people with depression may be self-medicating by smoking, albeit in a deadly way.”

This may be the reason why sleep-deprived adolescents are much more likely to take up smoking than their well-rested peers.

Brains of the Week

Encephalon #6, the neuroscience blog carnival, is up on Retrospectacle

Neurons on a Ferris Wheel

Synapse #6 is up on The Mouse Trap.

So, dolphins are dumb and manatees are smart?

Yesterday, 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 biologists with the elaborateness of the survival strategies an animal must develop to find food and avoid predators. Manatees have the lowest brain-to-body ratio of any mammal. But, as Dr. Reep noted, they are aquatic herbivores, subsisting on sea grass and other vegetation, with no need to catch prey. And with the exception of powerboats piloted by speed-happy Floridians, which kill about 80 manatees a year and maim dozens more, they have no predators:
“Manatees don’t eat anybody, and they’re not eaten by anybody,” Dr. Reep said.
But he also suspects that rather than the manatee’s brain being unusually small for its body, the situation may be the other way around: that its body, for sound evolutionary reasons, has grown unusually large in proportion to its brain.
A large body makes it easier to keep warm in the water — essential for a mammal, like the manatee, with a glacially slow metabolism. It also provides room for the large digestive system necessary to process giant quantities of low-protein, low-calorie food.
————————–snip——————————–
Manatees have a relatively thick cerebrum, with multiple layers that may, Dr. Reep suspects, indicate complexity despite a lack of folding.
In any case, he said, brain convolution “doesn’t seem to be correlated with the capacity to do things.”
More to the point, intelligence — in animals or in humans — is hard to define, much less compare between species, Dr. Reep said. Is the intelligence of a gifted concert pianist the same as that of a math whiz? Is a lion’s cunning the same as the cleverness of a Norwegian rat?
The manatee is good at what it needs to be good at.

The rest of the article focuses on manatees’ sensory capabilities, especially the somatosensory system. Manatees have vibrissae (long hairs, usually seen only around the faces of animals like cats and dogs), which are thought to be involved in the sense of touch, spread all over the body. The article incorrectly states that the only other mammal with vibrissae all over the body is rock hyrax. There is another one, though, which is much better studied in this regard – the naked mole-rat.
Also, the article states that manatee is unique among mammals in the ability to hear infrasound. That is also wrong – a lot of mammals, especially large mammals are capable of hearing infrasound. The best studied are elephants and whales, but it was also described in giraffes (von Muggenthaler, E., Baes, C., Hill, D., Fulk, R., Lee, A., (1999) Infrasound and low frequency vocalizations from the giraffe; Helmholtz resonance in biology, invited to the Sept. 2001 AZA conference, presented at the regional Acoust. Soc. Am. conference 2001.) and rhinos, while the infrasound vocalizations were made from okapis, tigers, horses and cows, as well as in some non-mammalian vertebrates, including crocodiles and perhaps some birds.
So, in light of our discussion yesterday, what do you think?

Brain in a Spin

Encephalon #5, the NeuroCarnival, is up on Developing Intelligence

Dolphins Are Intelligent!

Where 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, however, says it is not intelligence that created the dolphin super-brain — it’s the cold. To survive underwater, these warm-blooded animals developed brains that have a lot of insulating material — called glia — but not too many neurons, the gray stuff that counts for reasoned thinking.

Wow! Since when are glia “insulating material”? A few years ago, for my Neuroscience class, I had to remember at least 10 functions of glia – not one of them having anything to do with insulation, or even structural support. It’s all about function – neurons and glia work together to process information. Anyway, I will blame this on the stupidity of the reporter as I doubt that anyone with such archaic ideas would ever be allowed to dissect a dolphin and publish a study in a decent journal.

Yet while dolphins aren’t as smart as people tend to think, they are as happy as they seem. Manger said dolphins have a ”huge amount” of serotonin in their brains, which is what he described as ”the happy drug.”

Sure, if you get your science from Cosmo and Glamour. Do I really have to start listing all the functions of serotonin now? Or try to define “happiness” in such simplistic terms that it can be explained with a single chemical?
It is not quite clear, but it appears that Alon Levy agrees with the study. But Lindsay is having none of it. She cites the self-recognition paper as well as some personal testimony of the researcher who did that study. When that paper came out I was teaching a “Readings in Behavioral Biology” graduate seminar and all the neuro faculty showed up for class and tried valiantly to destroy the paper – with no avail. It is good.
Dolphins are darn smart. They play (check this pdf). They have complex communication and complex social interactions.
So, how does this kind of argument ever show up? Because of anthropocentrism. Two types of anthropocentrism, to be precise.
First, the concept of “intelligence” is often defined in human-like terms. If an animal can do stuff we do, it is deeemed smart. If it can be easily trained like our immature offspring can, it is smart. If it can talk, it is smart. If it builds structures, it is smart. BS. Intelligence has to be defined from the vantage point of that species: what makes ecological and evolutionary sense for that species to be able to do. Bees are smarter than ants because they have a more sophisticated ability to orient in space and time, not because they speak English, French and Chinese.
Now, don’t get me wrong now. Since we are intelligent, looking for intelligence in other animals may benefit from comparison to humans. The trouble is, people go for specifics of human capabilities, instead of a general idea what intelligence is.
Writing “Hamlet” is an ecologically relevant ability for humans. It kept old Will fed and clothed for a few months, after which he wrote the next play. Why would an insect need to write theater plays? It is not ecologically relevant to it. It does not aid survival and/or reproduction.
Intelligence is the ability to learn fast and learn a lot of pieces of information relevant to one’s ecology. It is the ability to hold many of those pieces in one’s mind simultaneously, to juggle them and analyse them and notice patterns. It is the ability to play with that information, to get new ideas and test them, to note and remember the results of those tests. It is the ability to use this novel informaiton to invent novel behaviors – doing different stuff at different places at different times. In short, intelligence is the ability to do science! Behavioral flexibility is the hallmark of intelligence – not the specific types of behaviors.
The second anthoropomorphism considers the underlying anatomy. Why should unrelated species of high intelligence have brains similar to us? They evolved their high intelligence at different times, in a different lineage, with different raw materials to work with, and under different ecological pressures, for different purposes.
Many birds are very intelligent – but in their own way. Clarke’s Nutcrackers, African Grey Parrots, pigeons, and most corvids (ravens, crows, jays) are highly intelligent creatures with huge capabilities for episodic memory (remembering spatial and temporal aspects of personal experiences), play, problem-solving, spatial orientation and perhaps even insight (planning for the future). And their brains look nothing like ours.
Octopus is a very smart animal. Its brain looks nothing like ours.
Macs and PCs can do all the same stuff (roughly), but look nothing like each other under the hood. Many kinds of harware can run the same kinds of software and do same kinds of things, so why should brains have to be all built the same way in order to make an animal “intelligent”?
So, leave the dolphins alone, at least until the Startide Rising.
Addendum: I forgot to note that glia are not white matter. Axons are white matter while neuronal bodies are grey matter. Glia surround both. It is the color of Schwann cells (a type of glia) that makes axons look whitish.
Thus, more grey matter means more neurons. More white matters means more connections. What is more important: gazillions of scattered cells, or the complexity of their connections? I’d say connections.
Addendum II: Dave Munger wrote a valid criticism of what I wrote here (and somehow I missed his earlier post on this subject):

I agree that intelligence is tremendously difficult to define, but I’d suggest that the perspective of an individual species is a poor place to start. Based on that notion, every organism can be said to be intelligent, because every organism is highly adapted to its environment. When we say an animal is “intelligent,” we’re defining intelligence from our own perspective: the point is to identify animals that are similar to ourselves.

I’m not sure that the point is to identify animals that are similar to ourselves, but even if it is, similar in what way? The general mental capabilities (that we still need to define) or specific capabilities (which I argued here against)?
As for looking at each species individually, I agree that it is impossible to do it in isolation, but eahc species can be compared with other species in its own group, e.g., birds with birds, insects with insect, and then broader, all with all. If we define, provisionally, intelligence as fast learning, high processing power and flexibility of behavior, then we can compare species without looking at specific items that are learned, specific informaiton that is processed and specific behaviors that are flexible. For some species, being inflexible is a great adaptive trait – doing everything by the pre-programed schedule can work wonderfully for a long period of time. Other species evolve flexibility which allows them to spread on a broader spatial range and perhaps allow them to survive a longer geological time.

Another time-scale in insect brains

Bumble Bees Can Estimate Time Intervals:

In a finding that broadens our understanding of time perception in the animal kingdom, researchers have discovered that an insect pollinator, the bumble bee, can estimate the duration of time intervals. Although many insects show daily and annual rhythms of behavior, the more sophisticated ability to estimate the duration of shorter time intervals had previously been known only in humans and other vertebrates.
————-snip——————
Bees and other insects make a variety of decisions that appear to require the ability to estimate elapsed durations. Insect pollinators feed on floral nectar that depletes and renews with the passage of time, and insect communication and navigation may also require the ability to estimate the duration of time intervals.
In the new work, the researchers investigated bumble bees’ ability to time the interval between successive nectar rewards. Using a specially designed chamber in which bumble bees extended their proboscis to obtain sucrose rewards, the researchers observed that bees adjusted the timing of proboscis extensions so that most were made near the end of the programmed interval between rewards. When nectar was delivered after either of two different intervals, bees could often time both intervals simultaneously. This research shows that the biological foundations of time perception may be found in animals with relatively simple neural systems.

Strengthen your synapses…

…by giving your brain a workout – read The Synapse #5 at Retrospectacle

The Power of the Thousand Electrodes

Mapping The Neural Landscape Of Hunger

The compelling urge to satisfy one’s hunger enlists structures throughout the brain, as might be expected in a process so necessary for survival. But until now, studies of those structures and of the feeding cycle have been only fragmentary–measuring brain regions only at specific times in the feeding cycle.
————–snip——————
In their paper, Ivan de Araujo and colleagues implanted bundles of infinitesimal recording electrodes in areas of rat brain known to be involved in feeding, motivation, and behavior. Those areas include the lateral hypothalamus, orbitofrontal cortex, insular cortex, and amygdala. The researchers then recorded neuronal activity in those regions through a feeding cycle, in which the rats became hungry, fed on sugar water to satisfy that hunger, and then grew hungry again.
“This allowed us to measure both the ability of single neurons to encode for specific phases of a feeding cycle and how neuronal populations integrate information conveyed by these phase-specific neurons in order to reflect the animal’s motivational state,” wrote the researchers.
By isolating and comparing signals from particular neurons in the various regions at various times in the cycle, the researchers gained insight into the roles neurons in those regions played in feeding motivation and satisfaction, they wrote. The researchers found that they could, indeed, distinguish neurons that were sensitive to changes in satiety states as the animals satisfied their hunger. They could also measure how populations of neurons changed their activity over the different phases of a feeding cycle, reflecting the physiological state of the animals.
Importantly, they found that measuring the activity of populations of neurons was a much more effective way of measuring the satiety state of an animal than measuring activity of only individual neurons in an area. And the more neurons they included in such populations, the more accurate the measure of that satiety state, they found.
Araujo and colleagues concluded that their analysis showed that while single neurons were preferentially responsive to particular phases in the metabolic status of the animal as it went through a hunger-satiety-hunger cycle, “when combined as ensembles, however, these neurons gained the ability to provide a population code that allows for predictions on the current behavioral state (hunger/satiety) of the animal by integrating information conveyed by its constituent units.”
“Our results support the hypothesis that while single neurons are preferentially responsive to variations in metabolic status, neural ensembles appear to integrate the information provided by these neural sensors to maintain similar levels of activity across comparable behavioral states,” they concluded. “This distributed code acting across separate hunger phases might constitute a neural mechanism underlying meal initiation under different peripheral and metabolic environments,” they wrote.

I’ve seen Miguel Nicolelis (one of the authors – the guy in whose Duke lab this was done) talk about some of his other research on rats (and monkeys) using the power of multielectrode recordings – on somatosensory perception. I did not know he was interested in hunger.
Leptin is a hormone that is associated both with hunger and with circadian rhythms. It provides a link between timing and the feeling of hunger, e.g., why you crave carbs (cereal and cookies) in the morning and fats (steak) in the evening. I’d love to know if they saw any influences in the time-of-day on their data.

Should we rewrite the textbook chapters on voltage-gated potassium channels?

Correct me if I am wrong, but I think this is really ground-breaking:
Study Finds Brain Cell Regulator Is Volume Control, Not On/off Switch:

He and his colleagues studied an ion channel that controls neuronal activity called Kv2.1, a type of voltage-gated potassium channel that is found in every neuron of the nervous system.
“Our work showed that this channel can exist in millions of different functional states, giving the cell the ability to dial its activity up or down depending on the what’s going on in the external environment,” said Trimmer. This regulatory phenomenon is called ‘homeostatic plasticity’ and it refers, in this case, to the channel protein’s ability to change its function in order to maintain optimal electrical activity in the neuron in the face of large changes within the brain or the animal’s environment. “It’s an elegant feedback system,” he added.
——-snip——–
Using this technique, postdoctoral fellow Kang-Sik Park revealed 16 sites where the protein is modified by the cell by via addition of a phosphate group. Further study–in which each of the sites is removed to reveal its role in modulation– followed by careful biophysical analyses of channel function by postdoctoral fellow Durga Mohapatra, revealed that seven of these sites were involved in the regulation of neuronal activity. Since each site can be regulated independently on the four channel subunits, the neuron can generate a huge (>1018) number of possible forms of the channel.
Using this mechanism, Kv2.1 channels are quickly modified, even mimicking the activity of other potassium ion channels. “The beauty of doing it with a single protein is that it is already there and can change in a matter of minutes. It would take hours for the cell to produce an entirely different potassium channel,” Trimmer explained.
Based on these results, Trimmer and his colleagues hypothesize that parts of the Kv2.1 channel protein interact in ways that make it either easier or harder for it to change from closed to open. The protein, they believe, can exist in either loose states that require low amounts of energy, or voltage, to change from one state to another or a locked-down state that requires lots of energy (high voltage) to open or close. The number and position of phosphate molecules are what determine the amount of voltage required to open the channel.

It just makes intuitive sense. It appeals to my aesthetic sense as well. And it is a great example of the power of evolution.
Potassium-Channel-2-2004.JPG

Neurons developing out ot Mesoderm?!

Snuck into the very end of this, otherwise very interesting article on neurobiology of cephalopods and moths, is this little passage:

As for flies, Tublitz outlined a tantalizing question, as yet unanswered, that has continued to take flight out of his lab for the last decade. Scientists for years, he said, have held “one hard rule” about what constitutes a neuron — that a neuron cell always arises from the ectoderm of a developing embryo. However, a discovery in Drosophila — fruit flies — has softened that assumption.
Cells arising from the mesoderm rest in a layer on top of the fruit fly’s nervous system, Tublitz explained. “These cells have all of the properties of nerve cells.” A slide shown during his talk displayed a long list of characteristics most often applied, with only few exceptions, to neurons. “Are these mesodermal cells nerve cells? I can’t answer that question conclusively, but we have generated data that suggest the answer may be ‘yes’.”