Optogenetics for conditioning without external stimuli

Airan and colleagues describe the work that they have done to genetically couple optic receptors to g-proteins (like cAMP) inside neuronal molecules. After developing the coupled receptor, they first show that their technique can recruit the same amount of cAMP after 60 seconds of exposure to light as the cell emits after 5 minute exposure [...]

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Mapping the genetics of the brain

Fascinating article by Jonah Lehrer about the work being done at the Allen Institute for Brain Science in Seattle, where they are attempting to create a genetic map of the human brain on a voxel scale. Here is one interesting tidbit:
They remain excited by the idea of working on the frontier of science, by the [...]

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Genes coding for neurotrophins in Drosophila

Neurotrophins are growth factor proteins that induce the survival and function of neurons, in large part prenatally but maintained to an extent through the rest of the lifespan as well. Major neurotrophins in vertebrates are nerve growth factor (sensory and sympathetic neurons), brain derived neurotrophic factor (mainly found in the PNS but also the hippocampus [...]

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The Adapted Mind book notes, part 1

This primer to evolutionary psychology is really more a tome than a book, as it has many different authors and approaches. Almost all of them are excellent, however. Here are my notes:

No instance of anything is intrinsically (much less exclusively) either “general” or “particular”–these are simply different levels at which any system of categorization encounters [...]

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Maze learning in C. elegans

Qin and Wheeler (2006) show that C. elegans can learn to travel through a T maze, and that their latency to reach the bacterial reward diminishes as the trial number increases. These nematodes only have 302 neurons, so any example of them learning associatively always fascinates me. They also have data showing that cat-2 dopamine [...]

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Describing age-related memory decline

Morrison and Hof (2007) review the mechanisms of action for memory decline in both Alzheimer’s diseases (AD) and non-AD individuals. For AD patients, the key factor seems to be neurofibrillary tangles (NFTs), which are correlated with the death of neurons in corticocortical curcuits, and which disconnect regions within the neocortex. Counter-intuitively, the most damaging changes [...]

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Meta brain imaging studies with multilevel kernel density analysis

There is so much empirical data on brain imaging studies where subjects perform a specific task that it is crucial to perform meta analyses on the data to see how reliable the results are. Wager et al. (2008) set out to review attempts to do just this, multilevel kernel density analysis (MKDA) approach, which recreates [...]

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The value of neuroscience: theory and application

Over at The Frontal Cortex, Jonah Lehrer muses on what he calls the “value of neuroscience”:
[L]earning about the brain can help constrain our theories. We haven’t decoded the cortex or solved human nature – we’re not even close – but we can begin to narrow the space of possible theories. We know, for instance, that [...]

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Hypothesizing on the mechanism behind life-extending capabilities of caloric restriction

Rodents fed 25-60% less than free-feeding controls can live up to 50% longer. This is a cross-species effect, holding true for yeast, rotifers, spiders, worms, mice, fish, and rats, and maybe non-human primates (although the longer the animal lives, the more expensive this effect is to establish). It is known to delay a number of [...]

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Tunneling nanotubes complicate neuronal signalling

Rustom et al (2004) found a new form of intercellular communication–tunneling nanotubes (TNTs). These are 50 to 200 nm in diameter and a length of several times that, and are used to transport organelles, as witnessed by enhanced green flourescent protein staining. When they treated cells with a substance to depolymerize F-actin, no TNTs were [...]

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