Reviewing gender
We’re back! Apologies for the long radio silence – day job, what can I say. Read more
Too much of a good thing?
We published another double header yesterday, this time on the role of particular cell types in visual responses. Both studies describe the effect of optogenetically manipulating various interneuron classes in mouse visual cortex. The papers are Lee et al. from Yang Dan‘s lab and Wilson et al. from Mriganka Sur‘s labs. And in fact, both were preceded by Atallah et al. from Massimo Scanziani’s lab, which appeared in Neuron earlier this year. Which means a bonanza of data on the effects of activating parvalbumin-expressing interneurons, and also a bonanza of different conclusions about their exact role – everyone comes to slightly different conclusions. Read more
A tale of three papers
I wanted the title of this post to be “A tale of two one two three papers” but I couldn’t figure out how to get strikethroughs in the title field. And I thought “A tale of two, make that one, no make that two again, oops now three” might be a bit cumbersome. As promised, here’s another installment of the discussion of what happens when we receive conceptually related/overlapping papers. It starts with a paper that appeared just yesterday in Neuron by Kenichi Ohki and colleagues describing how mouse visual cortex neurons that developed from the same neural progenitor cell tend to be more similar functionally than those that did not. Read more
Autism, synapses and mice – pairs division
Again, we’re behind on blogging – you guys are keeping us busy with great neuroscience – but here is the story of a pair of papers that appeared back to back in last week’s issue and a continuation of the discussion started here by Noah about the process of joint publication. The two papers by Tobias Boeckers and colleagues and by Eunjoon Kim and colleagues were independently submitted and both describe autism-like phenotypes of mice with mutations in the gene Shank2. In human studies, SHANK2 has been associated with rare cases of autism and these two mice add to the ever-growing list of rodents (according to SFARI.org, 17 rodent models debuted in 2011 alone) that are being created to investigate the functional consequences of genetic mutations linked to autism, in the hopes of understanding mechanisms underlying core symptoms. Read more
Positive feedback drives network (and manuscript) maturation.
It really is an embarrassment of riches here at Nature these days, what with so many excellent neuroscience-related studies emerging. Just in the last couple of weeks, we’ve had the following studies: … Read more
“There is no spoon…”: Paralyzed fish navigates virtual environment while we watch its brain
Sometimes an experiment will just reach off the page and slap you in the face, demanding attention. This happens to me every so often and I must admit, our latest paper from the lab of Florien Engert induced such an experience. There have been several cool, technical tours-de-force (is that proper grammar??) over the last few years involving different creatures navigating in a virtual environment while neuronal activity was monitored. These include a mouse running on a spherical treadmill, as well as a fly marching along a similar treadmill-style ball. But in these examples, having the subject head-fixed (for the stability of recordings in the brain, either with electrodes or through imaging) was moderately non-intrusive since walking motions were independent of the head. The same can’t be said for the subject in this latest example of a virtual reality navigator: a wriggling, swimming fish. Therefore, a more creative solution had to be sought and in a paper published online yesterday, Ahrens, Engert and colleagues decided that paralysis was the way to go in order to follow the neural activity of this navigating fish. Read more
Fear of the Light
It is commonly believed that distinct mini-networks of neurons, firing together, may be the means by which memories and other conceptual encoding requirements are handled in the brain. However, it is only recently that we have had the tools available to directly test the sufficiency of such a mechanism. Today, a new study in Nature from the lab of Susumu Tonegawa documents the ability to use light as a means to activate distinct subsets of neurons responsible for the encoding of fear memories. Read more
Parietal decision sequences – and more of mice and monkeys
Back in the 1990’s, one of the most intense battlegrounds in systems neuroscience was in monkey posterior parietal cortex. Labs competed to claim what a little strip of cortex called lateral intraparietal area (LIP) really does – decision, movement planning, attention, reward, or all of the above – mostly using single cell recording in behaving monkey. The experiments were (and still are) tough: standard operating procedure requires a well-trained monkey who will perform hundreds if not thousands of trials a day and then isolating neurons one at a time to find ones that respond during some interesting part of the trial. And then lots and lots of repetition so that you can average over many neurons. All things considered, it’s remarkable how much the field has been able to learn with this toolbox. Read more
The Fine Architecture of Learning and Joint Publication
You warily walk into a dark compartment, wondering if there is food inside. Suddenly there is a loud tone and you feel an uncomfortable surge of electricity through your feet. This goes without saying, but it won’t take long before you will learn to be afraid of that tone. However, over time, you hear the tone without the shock, and slowly (foolishly??) accept that the previous connection may no longer hold. Read more
Layer magic and monkey business
We’ve known for over a century that sensory cortex is arranged in distinct layers, each containing a different make up of neuronal types and projection patterns, but we don’t actually know that much about the actual computations performed in each layer. Today a paper from Massimo Scanziani’s lab takes a big step towards cracking the function of the bottom layer (layer 6) in mice. Layer 6 neurons project both to upper cortical layers and to the lateral geniculate nucleus in the thalamus, which itself is the primary input to cortex, and so are primed to play a large modulatory role. Using a monumental combination of optogenetics, intracellular recording, and behavioral testing, the paper convincingly makes the case that layer 6 controls the gain of visual responses of upper layer neurons (i.e. Read more
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Reviewing gender
Autism, synapses and mice – pairs division
The Fine Architecture of Learning and Joint Publication