Neuroscience posts
- March 21, 2013
- 04:17 PM
- 24 views
Image ALL the neurons!
by neuroecology in Neuroecology
So you want to image every neuron in the brain of a vertebrate? What kind of crazy man are you? Misha B. Ahrens, that’s who. In what can only be described as a “crazy awesome” experiment, Ahrens used a technique that’s been recently emerging called light sheet microscopy to image the activity of (nearly) every neuron [...]... Read more »
Ahrens, M., & Keller, P. (2013) Whole-brain functional imaging at cellular resolution using light-sheet microscopy. Nature Methods. DOI: 10.1038/nmeth.2434
- March 21, 2013
- 08:59 AM
- 118 views
Gazzaniga Book Signing at APS Convention
by sschroeder in Daily Observations
Few scientists know the brain as well as APS Past President Michael Gazzaniga does. A pioneer in cognitive neuroscience, Gazzaniga was the first researcher to study patients in whom the ... Read more »
Gazzaniga M. (2011) Interview with Michael Gazzaniga. Annals of the New York Academy of Sciences, 1-8. PMID: 21486292
- March 19, 2013
- 11:47 PM
- 74 views
A snake bit me, now I’m afraid of rope?
by Shelly Fan in Neurorexia
Memories allow us to survive and adapt in constantly changing environments. Fear memory especially warns us to avoid that jumpy hornet in the garden, or the slithering snake on the hiking trail. These memories aren’t very specific – this is evolutionarily beneficial as it allows us to respond to new but similar threats on the [...]... Read more »
Xu W, & Südhof TC. (2013) A neural circuit for memory specificity and generalization. Science (New York, N.Y.), 339(6125), 1290-5. PMID: 23493706
- March 19, 2013
- 04:41 PM
- 134 views
What is up with the "Dopamine Project"?
by TheCellularScale in The Cellular Scale
Someone is trying to make me eat my words.yum. (source)That someone is the Dopamine Project. I am on record as saying "It is better for the public to learn simplified bite-size science morsels than to learn nothing at all." And my specific example was that it's better for people to know that 'dopamine is a reward molecule' than to not even know the term dopamine.But sometimes things just go too far. The "Dopamine Project" is a website run by Charles Lyell with a stated 'self-help' purpose: "The Dopamine Project was founded to foster positive change by encouraging open-minded individuals to share readily available research into the connections between dopamine and a growing list of addictive behaviors." -About TabDoesn't sound too terrible, right? Share research about dopamine? sign me up! .... However, I don't see ANY research, or even references to research, on this website. In fact it's quite wootastic. Going through the posts, you get some gems like"A Message from you Dopamine Angel"and"Keeping a Dopamine Diary: Wrestling with Dopamine-Induced Ignorance"It's all about how 'good dopamine' makes you want things you should want (food) and 'bad dopamine' makes you want things that will hurt you later (addictive drugs for example). Basically the website's message is a self-help, self-control one with the word dopamine sprinkled all over it.The worst part is that not only does the website not include a single citation to a research paper, it actively rails against science. "The future depends on how long it takes scientists to discover what they haven’t been interested in discovering so far. Rather than wait for the mainstream scientists and media to get started, we’re reaching out to anyone interested in fostering positive change by raising dopamine awareness." -Welcome to the Dopamine Project Trust me, scientists want to understand dopamine. At the IBAGS conference half the talks related to dopamine, and there is a conference completely devoted to dopamine coming up in May. The specific action of dopamine is really really complex, and scientists are working really really hard to unravel its intricacies. This Charles Lyell guy is pulling out a typical woo card, implying that he knows what scientists don't want you to know. "If the thought of fostering positive change through dopamine awareness triggers a shot of dopamine that brings a smile to your face, this might be your chance to be among the top .001% who go on record as the first to understand and apply what we know about dopamine to make a difference." -Welcome to the Dopamine Project He also seems to feel personally attacked by Steven Poole's New Statesman article on Neurobollocks. Is the 'Dopamine Project' ridiculous and unscientific? Absolutely.Is it harmful and dangerous to people? ... Honestly, I'm not sure. Reading it certainly makes me want to throw up, but there are worse things for pseudoscience to encourage than self-control. I'm not sure if I should devour my earlier words quite yet. © TheCellularScaleTo read more on the confusing line between science and pseudoscience, see Michael Shermer's Scientific American article: Shermer M (2011). What is pseudoscience? Scientific American, 305 (3) PMID: 21870452... Read more »
Shermer M. (2011) What is pseudoscience?. Scientific American, 305(3), 92. PMID: 21870452
- March 19, 2013
- 10:09 AM
- 149 views
Need the Time? Ask a Rooster
by Elizabeth Preston in Inkfish
"The connection with the sun coming up is a misconception," asserts an article in the rural lifestyle magazine Grit. "Roosters crow all the time." Some roosters in Japan would like to loudly disagree. They've shown scientists that their crowing has everything to do with what time of day it is—something they don't even need the sun to know.
Tsuyoshi Shimmura and Takashi Yoshimura, both of Nagoya University in Japan, investigated whether a rooster's crowing is tied to its circadian clock. That is, does the bird's internal sense of night and day determine when it's noisiest? Or do roosters crow at random hours—"morning, noon and night, not to mention afternoon, evening and the parts of the day that don’t have names," according to a disgruntled neighbor-to-roosters quoted in the Grit story?
Like any scientists studying how animals follow the sun's rhythms, the researchers began by shutting their subjects indoors. In a controlled environment, they kept the roosters on a strict schedule of 12 hours in the light and 12 hours in the dark.
Recordings showed that the roosters did not crow at random. A sudden burst of crowing came two hours before the artificial dawn, and the birds gave another "cock-a-doodle-doo" immediately after the lights came on. (Though in their country, the authors point out, it's "ko-ke-kok-koh.")
Then the scientists turned the lights out entirely, keeping the birds in a permanent night. The roosters at first continued to follow crowing cycles of roughly 24 hours, with only their internal clocks keeping them on schedule. Over the course of two lightless weeks, this rhythm gradually wound down.
In the barnyard, though roosters need their circadian alarm clocks for any pre-dawn crows, they can rely on other cues to trigger their crowing at sunrise—say, the sun. So Shimmura and Yoshimura next checked whether light itself causes crowing.
Starting with roosters that were living in permanent night, they tried exposing the birds to a little bit of light at the dawn hour. A few of the roosters crowed. When the researchers used brighter and brighter light, more and more of the birds crowed in response, as if recognizing the sun. A sound recording of other roosters crowing also worked to set their birds off.
Yet just flipping on the lights wasn't enough to make a benighted bird start crowing. When the light and sound signals came at "dawn," the roosters readily responded. When researchers used the same signals later in the "day," their birds didn't respond as strongly. And when they tried the signals at "night," the roosters didn't crow at all.
Even though they were living in permanent dark, roosters weren't fooled by seeing a fake sun at any old time. To get them crowing in earnest, the signals of sunrise had to come at the same time that the birds' bodily alarm clocks rang.
Roosters seem to be expert timekeepers. This knowledge, though, may not make come as much consolation to their neighbors.
Shimmura, T., & Yoshimura, T. (2013). Circadian clock determines the timing of rooster crowing Current Biology, 23 (6) DOI: 10.1016/j.cub.2013.02.015
Image: by -JvL- (Flickr)
... Read more »
Shimmura, T., & Yoshimura, T. (2013) Circadian clock determines the timing of rooster crowing. Current Biology, 23(6). DOI: 10.1016/j.cub.2013.02.015
- March 19, 2013
- 01:23 AM
- 139 views
The Evolution of Religion
by Drexid in Neurobrainstorm
Religions tend to evolve and adapt to benefit a society the most. The first religion can be uncovered from ancient anthropomorphic sculptures 42,000 years ago.... Read more »
WU Fei-fei,JIN Li-ji,LI Xiao-yu,LI Hua-qiang,CAO Zhen-hui,YOU Jian-song,XU Yong-ping(Ministry of Education Center for Food Safety of Animal Origin,College of Life Science and Technology, Dalian University of Technology,Dalian 116024,China). (2012) Research progress in active ingredients and pharmacological effects of deer antler. Chinese Journal. info:/
- March 18, 2013
- 04:27 PM
- 110 views
Today in cognitive dissonance: celebrating “landmark” openness in a closed journal
by Zen Faulkes in NeuroDojo
A new editorial in The Journal of Comparative Neurology celebrates a paper that goes the extra mile in making its anatomical data available:
(The authors) provide an unprecedented level of access to their supporting data by publishing their full set of experimental outcomes in the form of virtual slides, or whole‐slide images.
The editorial nicely summarizes why archiving data from brain slices is particularly important. Brains are complex structures, and there is necessarily a lot of interpretation of what you see on microscope slides. (How many beginning students mistake air bubbles for amoeba?). Increasingly, many studies rely on stains that fade over time.
For comparative neuroanatomists, you can’t always guarantee that you will be able to get another brain from some interesting species. You can’t just go get a brain from a whale any time you want. There is a tradition of collecting and archiving interesting brains from all kinds of species in comparative neuroanatomy.
The editorial points out the advantages of archiving these data on the Internet rather than in print:
(A) typical virtual slide in the collection would require over 250 square meters of paper if printed at full resolution.
The irony of all this is that The Journal of Comparative Neurology is a paywalled, subscription based journal. And not just any subscription journal, but one with a breath-taking $30,860 price tag. And that’s for Internet access or print. If you want both, be prepared to add a few thousand to meet the new asking price of $35,489.
Guys, if openness and data sharing is good, and the limitations of print are bad, you’ve just made great argument for journals like PLOS ONE, PeerJ, the BioMed Central family, and their like. Why does your journal continue to exist in its current form?
Related posts
Got $30,000 to spare?
References
Gaillard F, Karten HJ, Sauvé Y. 2013. Retinorecipient areas in the diurnal murine rodent Arvicanthis niloticus: A disproportionally large superior colliculus. The Journal of Comparative Neurology: in press. DOI: 10.1002/cne.23303.
Karten HJ, Glaser JR, Hof PR. 2013. A landmark in scientific publishing. The Journal of Comparative Neurology: in press. DOI: 10.1002/cne.23329
Photo by topastrodfogna on Flickr; used under a Creative Commons license.... Read more »
Karten Harvey J., Glaser Jack R., & Hof Patrick R. (2013) A landmark in scientific publishing. Journal of Comparative Neurology. DOI: 10.1002/cne.23329
- March 18, 2013
- 02:01 PM
- 159 views
Autism Research in Psychological Science
by ebender in Daily Observations
April 2 is World Autism Awareness Day, recognized by the United Nations General Assembly for the purpose of improving the lives of people living with autism. According to the organization ... Read more »
Cook, R., Brewer, R., Shah, P., . (2013) Alexithymia, not autism, predicts poor recognition of emotional facial expressions. Psychological Science. info:/
- March 18, 2013
- 08:00 AM
- 109 views
The costs of being tall: lessons from giraffes
by Zen Faulkes in NeuroDojo
True facts about giraffes!
They’re tall. And I use the word precisely. They’re not just big; their legs are about half again as long as you’d predict based on their mass and bodies of other mammals.
Being tall has distinct consequences for the nervous system. The distances that signals have to travel might mean there is lots of lag between something happening out in the world, the signal getting to the brain, and the appropriate response going all the way back down to the muscles the animals use to move about.
There are ways around this distance problem. You can make axons bigger, which speeds up how fast they can send a signal, but that means you probably have fewer axons, which could mean lower sensitivity on the sensory side, or precision on the motor side.
A new paper by Heather More and colleagues try to figure out how the giraffe’s nervous system deals with all these great distances. They recorded the speed of reactions and the size of neurons in the sciatic nerve of giraffes. The average speed of signals in this giraffe nerve was about 50 meters per second, which is about the same as rats. Rats, it should be noted, are not tall. They’re not even big.
More and colleagues calculated that for a giraffe to be as quick and as responsive as a rat, the speed of signals would have to be around 200 m/s, which is the top speed in the entire animal kingdom (a record held by some shrimps). And to get to that point, their neurons would have to be two and a half times the diameter they actually found in the giraffes.
Looking at the sheer number of axons, More and colleagues also suggest that the giraffe is comparatively at a disadvantage compared to smaller mammals. If the giraffe’s sciatic nerve had the same number of axons for its size as the rat does, it would have about 50 times more axons than what giraffes actually have.
From this, the authors predict that giraffes are working with a bit of a neural and behavioural handicap. They should be less sensitive to the world around them, and slower to respond to it, than smaller animals. But this is still a prediction that needs testing. Getting some giraffes in the lab for the experiments might be a bit tricky.
P.S.—When I blogged about a previous paper with some of the same authors, one criticism in the comments was that the team used conduction velocity of action potentials to measure “responsiveness.” This paper does a much better job of laying out all the different elements that go into determining “responsiveness” in general. That said, they don’t make much progress on measuring all those other elements in this paper, but at least they recognize they exist.
Related posts
The elephant and the shrew, an axonal story
Reference
More HL, O'Connor SM, Brondum E, Wang T, Bertelsen MF, Grondahl C, Kastberg K, Horlyck A, Funder J, Donelan JM. 2013. Sensorimotor responsiveness and resolution in the giraffe. The Journal of Experimental Biology 216 (6): 1003-1011. DOI: 10.1242/jeb.067231
Top photo by ucumari on Flickr; used under a Creative Commons license.... Read more »
More H. L., O'Connor S. M., Brondum E., Wang T., Bertelsen M. F., Grondahl C., Kastberg K., Horlyck A., Funder J., & Donelan J. M. (2013) Sensorimotor responsiveness and resolution in the giraffe. Journal of Experimental Biology, 216(6), 1003-1011. DOI: 10.1242/jeb.067231
- March 18, 2013
- 06:07 AM
- 152 views
Transcranial Magnetic Stimulation: A Loud Warning
by Neuroskeptic in Neuroskeptic_Discover
Transcranial Magnetic Stimulation (TMS) is popular tool in neuroscience. A TMS kit is essentially a portable, powerful electromagnet, called a ‘coil’. Switching on the coil causes it to emit a magnetic pulse, and this magnetic field is strong enough to evoke electrical activity in the brain. So, by placing the TMS coil next to someone’s [...]... Read more »
Duecker F, & Sack AT. (2013) Pre-stimulus sham TMS facilitates target detection. PloS one, 8(3). PMID: 23469232
- March 15, 2013
- 01:26 PM
- 165 views
Is it 'Important' or is it 'valuable'?
by TheCellularScale in The Cellular Scale
We've recently discussed dopamine as a reward prediction signal. But that is really just the start of the complicated dopamine story. Dopamine's role in reward and punishment (by the hiking artist)Some research groups have also found that dopamine neurons respond to aversive stimuli, like an air puff to the face or an electric shock. This finding seems to be be completely incompatible with the idea that dopamine is a signal for reward. Luckily some scientists took the time to try to resolve this discrepancy. Bromberg-Martin, Matsumoto, and Hikosaka (2010) have written an excellent review paper explaining that some dopamine neurons do code for value (reward), but other dopamine neurons code for salience (importance). Differential Dopamine Coding (Bromberg-Martin et al., 2010 Fig 4)When researchers are recording from a value coding dopamine neuron, it looks like the neuron responds to reward and actually reduces its response to the air puff. This makes sense as a 'dopamine = good' signal.However, when a researcher is recording from a salience coding dopamine neuron, it looks like the neuron is responding equally to the good thing (reward) and the bad thing (air puff). This is confusing if you think 'dopamine = good', but makes sense if you think 'dopamine = important'. When the cue comes on (a light or a tone that signifies a reward is coming next or an air puff is coming next), these dopamine neurons fire if that cue means something. Instead of just being confused about why sometimes dopamine would code for value and sometimes it would code for salience, Hikosaka's group showed that these two types of neurons are actually separate populations, and even seem separated in space. (Bromberg-Martin et al., 2010 Fig 7B)The value dopamine neurons are more ventral in the (monkey) brain, while the salience dopamine neurons are more dorsal-lateral. Importantly these two populations of neurons go to slightly different parts of the striatum and receive signals from different parts of the brain. The review paper suggests that the salience coding neurons receive their input from the central nucleus of the amygdala, while the value coding neurons receive their input from the lateral habenula-RMTg pathway. The important thing here is that dopamine does not do just one thing to the brain. It doesn't just tell the rest of the brain 'yay, you won!' or 'you want that' etc... It says different things depending on different specific conditions. Dopamine doesn't 'mean' anything, the cell it comes from and the cell it goes to are what determine what it does. It certainly can't be classified as the 'love molecule' © TheCellularScaleBromberg-Martin ES, Matsumoto M, & Hikosaka O (2010). Dopamine in motivational control: rewarding, aversive, and alerting. Neuron, 68 (5), 815-34 PMID: 21144997... Read more »
Bromberg-Martin ES, Matsumoto M, & Hikosaka O. (2010) Dopamine in motivational control: rewarding, aversive, and alerting. Neuron, 68(5), 815-34. PMID: 21144997
- March 15, 2013
- 05:16 AM
- 174 views
How Neuroscientists Scan the Media
by The Neurocritic in The Neurocritic
In case you missed it, I had a guest post this week in Nature's SpotOn NYC series on Communication and the Brain (#BeBraiNY), held in conjunction with Brain Awareness Week. The theme concerned the challenges of engaging the public's interest in cognitive sciences, and communicating the knowns (and unknowns) of brain disorders:In the current funding climate of budget cuts and sequestration, there’s a wide latitude between overselling the immediate clinical implications of "imaging every spike from every neuron" in the worm C. elegans (as in the proposed Brain Activity Map Project) and ignoring science communication entirely, leaving it up to the university press office.Who occupies the middle ground between the industry cheerleader and the disinterested academic? Science bloggers, for one. Scientist bloggers comprise a growing segment of the science communication world.Many of us have been critical of how traditional media channels can distort the actual scientific results and mislead the public. With the mainstreaming of neurocriticism, I felt this topic had been discussed extensively in recent months, so I moved on to the responsibilities we face in presenting accurate information. Some examples were drawn from my posts on unusual neurological disorders, including Prosopometamorphopsia (a condition where faces look distorted on one side) and Othello Syndrome (delusional jealousy). Both posts can turn up on the first page of a Google search, so I do feel an obligation to be factual and informative.Another example was a critique of public brain scanning on Celebrity Rehab with Dr. Drew. Although I wrote that post (and a follow-up) in 2010, readers were finding them now because former program participants Mindy McCready and Dennis Rodman were in the news, for very different reasons. My guest post concludes with:Scientist bloggers serve an important function in the continuum of science communication. We should take our responsibility for presenting high quality, ethical information very seriously, to help stem the ongoing flood of neurocrackpottery.Amidst the SpotOn NYC series extolling the virtues of science blogging came a new paper suggesting that science blogs are inferior sources of information relative to traditional media (Allgaier et al., in press):Scientists may understand that neuroscience stories in legacy media channels are likely to be of higher quality than similar narratives found in blogs. Stories in social channels are often crafted on the fly, without the help of experienced editors who can point out holes in the narrative or who can insist on rewriting and revision. Blog posts also tend to be shorter narratives, bereft of the kind of complexity and nuance possible only in long-form journalism.Obviously, there's a lot of high quality "long-form" journalism (which is never defined in the paper), but a huge number of high quality, complex and nuanced blog posts can be found as well. The passage above sparked quite the discussion on social media. Here's one initiated by respected journalist, blogger, and science writer Carl Zimmer:Blogs versus journalism in neuroscience--IT LIVES!I found passages like the one I just quoted [the one above] to be puzzling on many levels. Science blogs pretty much came into existence as a way for scientists themselves to critique bad coverage in traditional media. And, ten years later, that remains a powerful tradition.The paper presents a romantic, uncritical view of the press. Speaking as a journalist, I can say this is a view we can ill-afford.What's more, neuroscience blog posts are very often deep, nuanced, and more accurate than "churnalism" driven by glib press releases.If neuroscientists are indeed avoiding blogs for this reason (no data provided in the paper that this is true), then they are sadly misguided.Eight others joined in the discussion, which is worth reading. One of the participants was Dominique Brossard, an author on the article in question.In brief, Allgaier et al. (in press) randomly contacted 1,248 "productive" neuroscientists who had published at least 8 articles in the preceding 2-year period. The survey participation rate was 21.3% in the US and 32.6% in Germany.The scientists responded to questions about three dimensions of public media channels, both traditional and online: (1) their personal use of these channels to “follow news and information about scientific issues”; (2) their assessment of the impact of scientific information in these channels on public opinion about science; and (3) their assessment of the impact of such information on “science-related decisions made by policymakers.” The respondents answered the questions with respect to a comprehensive list of traditional print or broadcast media, online analogs of those media channels, blogs, and content in social networks. Respondents were primarily male (78%) and over 40 (79%). Is this a typical sampling of neuroscientists? Obviously not, since it is gender-imbalanced1 and excludes most grad students and the average post-doc. The results in this group of participants suggested a preference for old media:The results of our survey indicate that the respondents in both countries remained heavily reliant on journalistic narratives, in both traditional and online forms, for information about scientific issues. Only a modest number of the surveyed neuroscientists reported that they use blogs or social networks to monitor such issues.Fig. 1a (modified from Allgaier et al., in press). Media use (in percentages) among neuroscientists in the United States and Germany. For the exact wording of the questions, detailed data, and significance information, consult supplemental table S1, available online at http://dx.doi.org/10.1525/bio.2013.63.4.8 [not online as of this writing].The over 40 crowd was more reliant on newspapers and valued online articles less than the younger set, who used social media more often as a source of popular science news. Women were less reliant on newspapers and printed pop sci magazines for science issue information than men.Do we really know if the participants consider blogs and social media to be inferior sources of information for the reasons quoted above? We do not. The authors were speculating, as they were in this paragraph (which elicited howls in the ... Read more »
Joachim Allgaier, Sharon Dunwoody, Dominique Brossard, Yin-Yueh Lo, & Hans Peter Peters. (2013) Journalism and Social Media as Means of Observing the Contexts of Science. BioScience. info:/10.1525/bio.2013.63.4.8
- March 15, 2013
- 04:18 AM
- 106 views
Decisions – conscious and unconscious
by Janet Kwasniak in Thoughts on thoughts
Previous experiments have looked at unconscious decision making. A new paper (citation below) confirms those experiments and adds more information. The authors are looking at the hypothesis that extrastriate and prefrontal neural regions are active during the encoding of decision information and continue to process that information during a subsequent distractor task. “It is [...]... Read more »
Creswell, J., Bursley, J., & Satpute, A. (2013) Neural Reactivation Links Unconscious Thought to Decision Making Performance. Social Cognitive and Affective Neuroscience. DOI: 10.1093/scan/nst004
- March 14, 2013
- 11:30 PM
- 128 views
The frugal brain
by Shelly Fan in Neurorexia
Long-term memory is costly. To encode a memory, the brain needs to synthesize many proteins that ultimately lead to changes in synaptic strength, which is thought to be the molecular mechanism behind memory storage. So what happens under nutrient starvation? Does memory storage fail? Plaçais, P. -Y. & Preat, T. To favor survival under food shortage, [...]... Read more »
Plaçais PY, & Preat T. (2013) To favor survival under food shortage, the brain disables costly memory. Science (New York, N.Y.), 339(6118), 440-2. PMID: 23349289
- March 14, 2013
- 08:30 PM
- 140 views
Neural cells derived from skin cells mature into brain cells in a Parkinson's monkey model
by beredim in Stem Cells Freak
In a new study, researchers from the University of Wisconsin-Madison have successfully transplanted, for the first time, stem cell derived neural cells into three monkeys with artificially induced brain damage. The cells were derived from induced pluripotent stem cells, which in turn were created by autologous skin cells. According to the researchers, the neural cells integrated perfectly into the lesions and were only visible because they were previously marked with a fluorescent protein. The study has implications in the field of developing personalised treatments for Parkinson's Disease.Full Story... Read more »
Marina E. Emborg, Yan Liu, Jiajie Xi, Xiaoqing Zhang, Yingnan Yin, Jianfeng Lu, Valerie Joers, Christine Swanson, James E. Holden, Su-Chun Zhang. (2013) Induced Pluripotent Stem Cell-Derived Neural Cells Survive and Mature in the Nonhuman Primate Brain. Cell Reports. info:/10.1016/j.celrep.2013.02.016
- March 13, 2013
- 04:03 PM
- 109 views
Do mirror neurons explain understanding, or is it the other way round?
by Han in Neurologism
(Alternate title: In Soviet Russia, Mirror Neurons Explain YOU!) A draft of this post has been sitting around for a few weeks, and while I’m happy with today’s sanity check, I still can’t help but suspect that I am missing something in the debate on “action understanding”. So I am happy to be convinced that [...]... Read more »
Rizzolatti G, Fogassi L, & Gallese V. (2001) Neurophysiological mechanisms underlying the understanding and imitation of action. Nature reviews. Neuroscience, 2(9), 661-70. PMID: 11533734
- March 13, 2013
- 10:12 AM
- 150 views
ECT Reverses Depression Brain Connectivity Deficit
by William Yates, M.D. in Brain Posts
Electroconvulsive treatment (ECT) remains one of the most effective treatments for major depressive disorder (MDD).The mechanism of action for ECT in MDD is unclear. Research targeting brain changes in ECT is an important pathway to understanding the mechanism of action for ECT.Patients with MDD show disruptions in brain functional connectivity as measures by functional magnetic resonance imaging (fMRI). The connectivity abnormalities in MDD have included changes in limbic, cortical and default networks.Abbott and colleagues recently published an analysis of resting state connectivity changes with ECT in a series of subjects with MDD. Key elements of the design of their study included:Subjects: 12 subjects with MDD with an average age of 66 years including three subjects with psychotic depressionECT parameters: Subjects received an average of 11 standard right unilateral or bitemporal treatmentsfMRI: Functional connectivity measures were assessed before and after ECT using independent component analysis techniquesStatistical analysis: Connectivity measures were compared within subjects pre and post ECT using paired t-tests. Additionally, subjects were compared to a group of non-depressed individual using two-sample t-tests The key findings from the study included:At baseline depressed subjects showed deficits in connectivity involving the posterior default mode network, the dorsomedial prefrontal cortex and the dorsolateral prefrontal cortexRemission of depression in ECT-treated subjects reversed the baseline deficits in posterior default mode network, the dorsomedial prefrontal cortex and the dorsolateral prefrontal cortexRemission with ECT was specifically linked to changes functional connectivity in the dorsomedial prefrontal cortex and the dorsolateral prefrontal cortex The authors note their findings may be useful in the eventual development of identifying MDD subjects most likely to benefit from ECT. Additionally, they note research into the mechanism of action of ECT may provide insight into less intense and more accessible treatment approaches such as transcranial magnetic stimulation therapies.This is an important study and holds promise that better targeted treatment for MDD may include non-pharmacologic brain stimulation approaches.Interested readers can learn more about the specifics of this manuscript by clicking on the link below.Photo of black-bellied whistling ducks from Venice, FL rookery from the authors files.Abbott, C., Lemke, N., Gopal, S., Thoma, R., Bustillo, J., Calhoun, V., & Turner, J. (2013). Electroconvulsive Therapy Response in Major Depressive Disorder: A Pilot Functional Network Connectivity Resting State fMRI Investigation Frontiers in Psychiatry, 4 DOI: 10.3389/fpsyt.2013.00010... Read more »
Abbott, C., Lemke, N., Gopal, S., Thoma, R., Bustillo, J., Calhoun, V., & Turner, J. (2013) Electroconvulsive Therapy Response in Major Depressive Disorder: A Pilot Functional Network Connectivity Resting State fMRI Investigation. Frontiers in Psychiatry. DOI: 10.3389/fpsyt.2013.00010
- March 13, 2013
- 02:40 AM
- 264 views
Brain Lateralization - Logical Left vs Creative Right
by Vivek Misra in Beautiful Mind
Broad generalizations are often made in popular psychology about one side or the other having characteristic labels, such as "logical" for the left side or "creative" for the right. These labels need to be treated carefully; although a lateral dominance is measurable, both hemispheres contribute to both kinds of processes.In psychology and neurobiology, the theory is based on what is known as the lateralization of brain function. So does one side of the brain really control specific functions? Are people either left-brained or right-brained? Like many popular psychology myths, this one has a basis in fact that has been dramatically distorted and exaggerated.Language functions such as grammar, vocabulary and literal meaning are typically lateralized to the left hemisphere, especially in right handed individuals. Although 95% of right-handed people have left-hemisphere dominance for language, 18.8% of left-handed people have right-hemisphere dominance for language function. Additionally, 19.8% of the left-handed have bilateral language functions. Even within various language functions (e.g., semantics, syntax, prosody), degree (and even hemisphere) of dominance may differ. The processing of visual and auditory stimuli, spatial manipulation, facial perception, and artistic ability are represented bilaterally, but may show right hemisphere superiority. Numerical estimation, comparison and online calculation depend on bilateral parietal regions while exact calculation and fact retrieval are associated with left parietal regions, perhaps due to their ties to linguistic processing. Dyscalculia is a neurological syndrome associated with damage to the left temporo-parietal junction. This syndrome is associated with poor numeric manipulation, poor mental arithmetic skill, and the inability to either understand or apply mathematical concepts. The right brain-left brain theory grew out of the work of Roger W. Sperry, who was awarded the Nobel Prize in 1981. While studying the effects of epilepsy, Sperry discovered that cutting the corpus collosum could reduce or eliminate seizures.However, these patients also experienced other symptoms after the communication pathway between the two sides of the brain was cut. For example, many split-brain patients found themselves unable to name objects that were processed by the right side of the brain, but were able to name objects that were processed by the left-side of the brain. Based on this information, Sperry suggested that language was controlled by the left-side of the brain.Depression is linked with a hyperactive right hemisphere, with evidence of selective involvement in "processing negative emotions, pessimistic thoughts and unconstructive thinking styles", as well as vigilance, arousal and self-reflection, and a relatively hypoactive left hemisphere, "specifically involved in processing pleasurable experiences" and "relatively more involved in decision-making processes". Additionally, "left hemisphere lesions result in an omissive response bias or error pattern whereas right hemisphere lesions result in a commissive response bias or error pattern." The delusional misidentification syndromes, reduplicative paramnesia and Capgras delusion are also often the result of right hemisphere lesions. There is evidence that the right hemisphere is more involved in processing novel situations, while the left hemisphere is most involved when routine or well-rehearsed processing is called for. Later research has shown that the brain is not nearly as dichotomous as once thought. For example, recent research has shown that abilities in subjects such as math are actually strongest when both halves of the brain work together.Taylor, I. & Taylor, M. M. (1990). Psycholinguistics: Learning and using Language. Pearson. ISBN 978-0-13-733817-7. p. 367Beaumont, J.G. (2008). Introduction to Neuropsychology, Second Edition. The Guilford Press. ISBN 978-1-59385-068-5. Chapter 7Ross, E., & Monnot, M. (2008). Neurology of affective prosody and its functional–anatomic organization in right hemisphere Brain and Language, 104 (1), 51-74 DOI: 10.1016/j.bandl.2007.04.007... Read more »
Ross, E., & Monnot, M. (2008) Neurology of affective prosody and its functional–anatomic organization in right hemisphere. Brain and Language, 104(1), 51-74. DOI: 10.1016/j.bandl.2007.04.007
George MS, Parekh PI, Rosinsky N, Ketter TA, Kimbrell TA, Heilman KM, Herscovitch P, & Post RM. (1996) Understanding emotional prosody activates right hemisphere regions. Archives of neurology, 53(7), 665-70. PMID: 8929174
Dehaene, S. (1999) Sources of Mathematical Thinking: Behavioral and Brain-Imaging Evidence. Science, 284(5416), 970-974. DOI: 10.1126/science.284.5416.970
Dehaene, S., Piazza, M., Pinel, P., & Cohen, L. (2003) THREE PARIETAL CIRCUITS FOR NUMBER PROCESSING. Cognitive Neuropsychology, 20(3-6), 487-506. DOI: 10.1080/02643290244000239
Hecht, D. (2010) Depression and the hyperactive right-hemisphere. Neuroscience Research, 68(2), 77-87. DOI: 10.1016/j.neures.2010.06.013
Devinsky, O. (2009) Delusional misidentifications and duplications: Right brain lesions, left brain delusions. Neurology, 72(1), 80-87. DOI: 10.1212/01.wnl.0000338625.47892.74
- March 12, 2013
- 02:28 AM
- 199 views
What Is This Thing Called Neuroscience?
by The Neurocritic in The Neurocritic
"It depends upon what the meaning of the word 'is' is." -President Bill Clinton, August 17, 1998image: Brain electrodes, by laimagendelmundoDr. Vaughan Bell at Mind Hacks wrote a terrific post on The history of the birth of neuroculture as a follow-up to his Observer piece on Folk Neuroscience. That article explained how neuro talk has invaded many aspects of everyday discourse. In the new post he briefly covers the history of modern neuroscience, a necessary prelude to contemporary neuroculture:Neuroscience itself is actually quite new. Although the brain, behaviour and the nervous system have been studied for millennia the concept of a dedicated ‘neuroscience’ that attempts to understand the link between the brain, mind and behaviour only emerged in the 1960s and the term itself was only coined in 1962. Since then several powerful social currents propelled this nascent science into the collective imagination.To me, those dates seem quite recent in relation to brain research that has been conducted for centuries. Was there no neuroscience research prior to the 60s? My general perception is that ‘neuroscience’ research has been around a lot longer than that, even if it wasn't called by that precise name. It might have been called psychobiology (Yerkes, 1921), neurobiology (Brodmann, 1909),1 neurophysiology (1938) or neurochemistry (Lewis, 1948), but the types of questions asked and the experiments performed appear to be in line with much of what passes as a dedicated neuroscience in modern times. Here's Dr. Nolan D.C. Lewis speaking at the 96th Annual Session of the American Medical Association, Atlantic City, NJ, June 13, 1947 (Lewis, 1948):The actual nature of the thought processes is annoyingly elusive. What is the nature of thought? It is probably a manifestation of energy, but one can ask many questions about this. ... Do small areas of intact brain produce thoughts? Does the brain produce the mind independently or is it an instrument used by some other somatic processes or agents in the body? Does the brain itself think or is it a transmission center utilized by some other force? Is the mind the product of cerebral matter or is it dependent on something else which governs it? Can matter think? Either matter can produce mind or it cannot. Is mind a unique form of matter different from any other known forms of matter? While these questions and problems are probably not solvable by means of present technics, they are challenging, approachable and must eventually become elucidated if we are to get to the core of mental disorders.2What's in a name?I became curious enough to investigate whether the term ‘neuroscience’ was actually coined in 1962. @AliceProverbio confirmed that "Francis Schmitt used the term Neuroscience for the first time in 1962 to name his Neuroscience reserch group [at] MIT". I found the paper in the Journal of the History of Neurosciences that clearly recognizes the role of Schmitt, but it also opined that the word might have been invented earlier (Adelman, 2010):...the word might have been coined by Ralph Gerard in the early 1950s...Does it really matter when the word itself was first used? No, not for Vaughan's history of the birth neuroculture. I'm not going to get to the bottom of who should get credit, either. But I do find it interesting to see how the word is used in various historical contexts.Not to be outdone by MIT, Harrison (2000) reviews the contributions and recollections of Five Scientists at Johns Hopkins in the Modern Evolution of Neuroscience, including those of pioneering neurophysiologist Professor Vernon Mountcastle:‘In the 1940’s, and on, this place [Johns Hopkins University] was red hot for the development of Neuroscience’.Noted historian of neuroscience Professor Stanley Finger, in his review on Women and the History of the Neurosciences, named several famous women neuroscientists of the 19th century (Finger, 2002):3 Women have been underrepresented in the early years of the neurosciences, much as they have been in other scientific endeavors. Nevertheless, the names of many important women contributors stand out if one begins in the latter part of the 19th century...Two women, who worked in part with their husbands but also achieved greatness on their own as the 19th century drew to a close and the 20th century began, are Augusta Marie (Dejerine-) Klumpke (1859-1927), who was married to Joseph Jules Dejerine (1849-1917), and Cécile Mugnier Vogt (1875-1962), who was married to Oskar Vogt (1870-1950)....Three other famous women neuroscientists from the later period are Christine Ladd-Franklin (1847-1930), Maria MichailovnaManasseina (also known as Marie de Manacéine, (1843-1903), and Margaret Floy Washburn (1871-1939). But in describing the vision of Professor Francis O. Schmitt in founding the Neurosciences Research Program at MIT, Adelman (2010) gets the last word on ‘neuroscience’:Ideally, Schmitt and his colleagues thought, the various physical, biological, and neural sciences could be brought together to attack a single goal, and what a goal — the ultimate one of all science and philosophy — how does the mind/brain work! Every field with some involvement in mind-brain studies would be included, from the molecular and subcellular areas of cell biology to the higher reaches of psychology and psychiatry. Such areas as cognitive psychology might not be able to contribute much to neurobiology; parallel fibers and psychophysical parallelism have little in common. But this field could pose major questions about higher brain function and the mechanisms of thinking, with molecular genetics perhaps providing answers about mechanisms operating at subcellular levels of the nervous system. Ha, ha! So much for the modern convergence of brain and behavioral sciences...Footnotes1 Dr. Korbinian Brodmann worked as an Assistant in the Neurobiological Laboratory of the University of Berlin.2 It goes without saying that modern techniques have opened up new avenues of study. And that ethical standards for the proper conduct of human and animal research (e.g., The Purring Center in Cats) have improved... Read more »
Adelman, G. (2010) The Neurosciences Research Program at MIT and the Beginning of the Modern Field of Neuroscience. Journal of the History of the Neurosciences, 19(1), 15-23. DOI: 10.1080/09647040902720651
LEWIS, N. (1948) SUGGESTIVE RESEARCH LEADS IN CONTEMPORARY NEUROCHEMISTRY. JAMA: The Journal of the American Medical Association, 136(13), 866. DOI: 10.1001/jama.1948.02890300016005
- March 12, 2013
- 01:43 AM
- 175 views
Correction to post on Rolfs paper
by Janet Kwasniak in Thoughts on thoughts
A month ago, I posted (here) on a paper reported in ScienceDaily. (citation below) I had not read the paper but commented on a quote of the author, included in the ScienceDaily item, which to me implied a dated understanding of a division between perception and cognition. The authors have kindly sent me a copy [...]... Read more »
Rolfs, M., Dambacher, M., & Cavanagh, P. (2013) Visual Adaptation of the Perception of Causality. Current Biology, 23(3), 250-254. DOI: 10.1016/j.cub.2012.12.017
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