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
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
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. Shank2 is a scaffolding protein that regulates excitatory synapse function by holding together various molecules such as neurotransmitter receptors and signaling proteins. Mutations in another member of the same gene family, SHANK3, are also associated with human autism, and mutant mice display behaviors reminiscent of ASD symptoms, such as social deficits and obsessive behavior. So this protein family, and more generally, glutamatergic transmission, is potentially one promising line of investigation. Read more
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
The (highly abbreviated) life story of a paper appearing in Nature often goes something like this: ideas are birthed and experiments envisioned. Pilot experiments are run, yielding beautiful preliminary data. Replication and controls are then gathered over the course of months, if not years of hard labor. The paper is written, submitted, and reviewed. A few (two is typical) rounds of review and revision later, it is published (with highly variable degrees of reviewer and editorial unanimity). But this is by no means the end, rather, just a milestone in the evaluation process by the community. In journals, post-publication evaluation has traditionally occurred in the form of peer-reviewed follow-up papers or formal commentary. Read more
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
I’m on the road (attending a symposium at MIT: New Insights on Early Life Stress and Mental Health) so this one’s going to be brief. Neural prosthetics are an exciting interface between basic research and technology, an area where the path from fundamental discoveries in the organization and function of the brain to translational advances has been remarkably clear. Cochlear implants have already demonstrated their utility for replacing/enhancing auditory function, and more and more promising advances are coming out all the time in retinal implants. Motor prostheses are another exciting area with the promise to restore motor control to paralyzed individuals and today’s paper by Lee Miller and colleagues represents another step towards a potential prosthetic for spinal injury patients. Read more
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
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
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