obese patients have lower levels of the dopamine D2 receptor in the caudate than lean patients. Low levels of D2 receptors results in lower responses to natural rewards such as food. So this means that people with low levels of D2 receptors could be overeating because food just isn't as "good" to them. It tastes the same (they recorded similar levels of how pleasant a chocolate shake was), but it just doesn't cut it in the brain, possibly prompting patients to continue eating to make up for the food reward they are missing.
One of the things I found incredibly cool about this study is how similar the changes in D2 receptors are between obesity and substance addiction, particularly cocaine
Over time, the reward processing appears to shift from the ventral to the dorsal striatum, which appears to be at least partially responsible for the craving associated with addiction.
Do the obese patients have lower D2 levels in the striatum because they compulsively overeat? Or do they compulsively overeat because they have lower D2 levels in the striatum? While the differences scene in the TAQ1A gene are interesting and imply that some initial differences may be innate, environmental factors may still play a very strong role.

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The art of competitiveness | The San Diego Union-Tribune

In his book, “A Whole New Mind: Why Right-Brainers Will Rule the Future,” Daniel Pink makes the case that we have entered the Conceptual Age and that certain right-brain skills are essential to economic success

Tags: economy, technology, industry, education, design, culture, art, brain, emotion, intelligence, creativity, book_review on 2008-10-31 -All Annotations (1) -About

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Scientists Identify Brain's 'Hate Circuit' - Yahoo! News

"hate circuit"? "implications in criminal cases"? and again about the insula (see stuff on smoking, cocaine use)

Tags: brain, woo, emotion on 2008-10-29 -All Annotations (1) -About

in list: watch for responses

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Neurophilosophy : Erasing memories

Tags: neuro, brain, memory, PTSD on 2008-10-25 -All Annotations (3) -About

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Memories Selectively, Safely Erased In Mice

see Mo's write-up and related links: http://scienceblogs.com/neurophilosophy/2008/10/erasing_memories.php

Tags: brain, neuro, memory on 2008-10-25 and saved by3 people -All Annotations (3) -About

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Mind Hacks: Towards a neuropsychology of religion

follow links, see Amy Tan's TED talk on creativity - http://www.ted.com/index.php/talks/amy_tan_on_creativity.html

Tags: religion, atheism, psychology, neuro, brain, evolution, culture, anthropology, philosophy, video on 2008-10-23 and saved by3 people -All Annotations (1) -About

in list: religion

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Pure Pedantry : Brain to Muscle Link in the Monkey

note PP and NeuroPhilosophy's reservations in expecting clinical applications to humans and complex motor tasks; NP's discussion of electrode position (and pics)

Tags: neuro, brain, plasticity, research, prosthetic, science_is_a_method on 2008-10-21 -All Annotations (1) -About

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Neurotopia (version 2.0) : Exercise: Feeling the burn is good for your brain

note writing style

Tags: exercise, brain, neuro, neurogenesis, learning, memory, cancer, research on 2008-10-21 -All Annotations (2) -About

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Seedmagazine.com | MIND08 | Henry Markram: Designing the Human Mind

Tags: brain, model, blue_brain, research, technology, computer, design, video on 2008-10-17 and saved by2 people -All Annotations (1) -About

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Not Exactly Rocket Science : The brain's addiction centre

Tags: smoking, nicotine, addiction, brain, research on 2008-10-14 -All Annotations (2) -About

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Mind Hacks: Ladies and gentlemen we're floating in space

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Neurophilosophy : New memories require new brain cells

This study shows that inhibiting neurogenesis has strikingly different consequences in two distinct regions of the brain. In the olfactory bulb, it leads to significant shrinkage but apparently does not alter smell-related behaviour. In the hippocampus, the effect on structure is not so marked, but it is clear that newly-generated neurons are necessary for the processes of learning and memory. The role of new cells in memory formation is, however, still unclear.

Tags: brain, neuro, neurogenesis, memory, stem_cell, olfaction, aging, science_is_a_method on 2008-10-09 and saved by2 people -All Annotations (9) -About

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strong evidence that the continuous generation of new neurons is critical for brain function, and that the newly-generated cells perform two distinct roles which are critical for tissue maintenance in the olfactory system and for the formation of two distinct forms of memory.
Newborn neurons generated in the SVZ migrate along a pathway called the rostral migratory stream to populate the olfactory bulb
Cre-mediated recombination, which allowed them to label neural stem cells for long periods of time. It also labelled the neurons generated from them, as they inherit the stem cell during cell division. The method involved engineering mutant mice in which the gene encoding Cre recombinase is under the control of a stretch of regulatory DNA which normally activates a gene called nestin in neural stem cells. These animals were then mated with several other mutant strains, each enginnered to possess a "reporter" gene encoding a fluorescent protein. In this system, the activity of Cre recombinase is induced by a drug called tamixifen. Thus, when the offspring of the mutant mice strains are treated with this compound, Cre causes reshuffling of the genes, so that the reporters are activated only in the neural stem cells.
The researchers then investigated what would happen in the olfactory bulb if they aborted the supply of new neurons from the SVZ. To do so, they used the same genetic approach to eliminate the newborn cells. In this case though, the first strain of mutants was crossed with another whose cells contained the gene encoding diptheria toxin unde the control of regulatory DNA which normally switches on a gene during the early stages of neuronal differentiation. When tamixifen is administered in the offspring produced from this mating, Cre activation in causes the toxin to be synthesized as soon as differentiation begins, and the newborn cells are killed.
because the new method labelled cells for far longer than previous ones, this study provides more details.
while neurogenesis was necessary to maintain the structure of the olfactory bulb, it was not in this case required for olfactory function. This is at odds with earlier findings, and so will need to be confirmed further with more tests of olfactory behaviour.
the number of cells in the dentate remained constant for up to 6 months. (By contrast, the hippocampi of the control animals increased in size.) But it did have dramatic effects on spatial memory and associative learning - the mutant mice were unable to learn their way around a maze, and did not exhibit fear behaviour

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A Conversation With Nancy C. Andreasen

Tags: brain, psychology, drugs, aging, alzheimer's, schizophrenia, complexity, interview, neuro on 2008-10-09 and saved by2 people -All Annotations (3) -About

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Direct Recording Shows Brain Signal Persists Even In Dreamless Sleep

"What we've shown provides a bridge between the fMRI work many scientists are doing now and the earlier work involving electrical recordings from the brain that emphasized slow activity," says He. "Bringing those two fields together may give us some very interesting insights into the brain's organization and function."

Tags: brain, neuro, fmri, research, science_is_a_method on 2008-10-09 -All Annotations (0) -About