herbbread

The gamma-band simply refers to oscillations observed in EEG, intracranial EEG, or MEG which has a frequency between anywhere from 30Hz to 200-300Hz. While the exact mechanism by which gamma oscillations occur isn't quite understood yet, we do know that any change in the local field potential measured by EEG is likely synchronized synaptic activity measured from the dendrites of pyramidal cells. While thalamo-cortical loops can give rise to gamma oscillations, it is by no means the only way to generate gamma activity. Some groups have shown that the cortex can generate its own gamma oscillations, most likely mediated by the inhibitory interneurons. Cardin, et al. (2009) Nature Gamma oscillations have become a "hot" neuroscience topic over the last few years because it has been correlated to various higher order cognitive processes, anywhere from the representation of visual information to language processing. You are right that expert meditators have shown the ability to modulate various measures of brain activity (included gamma activity), but whether this is the direct cause of the modified consciousness or simply an epiphenomenon is unknown.

My thought is that I'd much rather spend my time doing something rather than continue to age while doing nothing. I'd spend my time reading, creating, writing etc so that the journey wasn't a complete waste of time. I think the idea for "going to sleep" while on these interstellar or interplanetary voyages is simply that the ship doesn't have enough room or energy to allow however many hundred colonists/explorers happy and alive for that long. In that case, so be it, I'll go to sleep. But if I could, I'd want to stay awake. Just personal preference. But I guess it's very situationally dependent. In terms of preventing muscle atrophy, I do believe there are ways to deliver electric pulses to the muscles to keep them contracting the slow muscle atrophy. I don't think it's ever as good as actually using your muscles constantly, but the technology is available and very simple.

I completely agree with PhDwannabe. From what we understand now, it is highly unlikely that the brain stores all sensory information encountered, but that this information is simply unavailable to the conscious mind. In fact, many of the low level sensory processing systems in the brain spend enormous energy in trying to reduce the dimensionality of the inputs it's receiving in attempts to extract the most salient and relevant pieces of information. Much of the rest of the "irrelevant" information is thought to be lost. With respect to the video the OP posted, I'm fairly certain this work is referencing one of the following two papers by Tom Mitchell's group at CMU: Shinkareva et al. (2008) PLoS One Mitchell et al. (2008) Science While this work is quite interesting, and a nice combination of neuroscience and machine learning techniques, it is far from what you might imagine to be "mind reading". In the second paper, the measure of "decoding" various nouns was simply a binary discrimination between two randomly chosen words resulting in statistically significant accuracies above chance. While impressive, this is far from decoding a single concept from an infinite sea of possible thoughts.

So while "suspended animation" as imagined by most science fiction authors isn't quite available yet, it is common to medically induce a coma in particular types of patients. In particular, patients who are in status epilepticus (basically a seizure which doesn't end), are given large doses to benzodiazepines or other anticonvulsants to induce a state of coma. In terms of nutrition, gastronomy tubes are typically used which allow for nutrient-rich fluids to be pumped directly into the stomach. Many stroke patients or patients at risk of aspiration who lose the ability to safely swallow food will often have a g-tube placed to allow nutrition to be obtained. Finally, respirators can allow patients who have no control over their breathing to continue obtaining oxygen. So, yes you can "sedate" someone for a long period of time. However, during this time, you still "age" unlike what is suggested by many scifi authors. Whether people would want to remain in this state during a long voyage through space, however, is a completely different matter. I personally would probably prefer to be awake for the journey if I do indeed age while sedated anyway. Why waste a part of your life asleep when you can do other stuff?

Hmm... I'd probably have things like "cognitive/behavioral", "cellular/molecular", "systems/circuits", "computational/theoretical" and "clinical" in my first nodes

Thanks for the help guys. I'll look a little more into it and see what I can find. If it would require constant calibration, and the measurements weren't that reliable, I'd be more skeptical about any results I actually obtained, and it might not be that useful for what I had in mind. Thanks again.

Thanks for the advice. So the unfortunate thing about dragon boat paddles is that they aren't oars and so aren't attached to the boat and have no fixed pivot point. They're used just like canoe paddle where the paddler has to hold onto the whole paddle (much less efficient than rowing, but I say a lot more fun). So are there strain gauges that are sensitive to such small changes as might occur in a bending paddle? And thanks for that site, it looks really useful. I'll take a look at what I can find and see how much experience I might need to put something together as cheaply as possible.

So I've been thinking for a while on ways to measure the force on a paddle (like canoe paddle). I do a lot of dragon boating (like a giant canoe with 20 people in it) and I wanted a way to be a little bit more quantitative about performance on our team. I've researched a few things and it seems that the best way to do this might be to attach a strain gauge to the shaft of the paddle and measure bending of the shaft as a proxy for actual force. I've also though of mounting some type of force sensor on the paddle itself, but I read one small journal article detailing a groups experiment with a force sensor and found that simply entering the water with the paddle marked the biggest change recorded force. I was imagining that whatever signal I record would go into a small waterproof box mounted on the shaft with electronics and a bluetooth transmitter to send the data to my phone. I have little experience with putting together such electronics, so I wanted to ask to see if anyone might have any idea how much work putting together something like this to be, how much it might cost, and any recommendations on how to go about it. Thanks in advance!

As far as I understand, all vessels have three layers, the tunica intima, tunica media, and tunica adventitia. The tunica intima is the internal layer and mainly consists of a layer of endothelial cells. This is the layer that is in contact with the blood and prevents clotting of blood while the endothelial layer is undamaged. The tunica media comes next and consists of elastic fibers, connective tissue, potentially smooth muscles. This layer is typically the thickest. The outer layer is the tunica adventitia and is also composed of connective tissue. I believe the relative thicknesses and compositions of the different layers depends on where in the circulatory system they occur. Thus, arteries, as pressure vessels, require a thicker tunica media (more elastic fibers, etc.)

Right, so proteomics might refer to a given combination of a large number of upregulated and downregulated proteins as a potential biomarker for cancer rather than the expression of a single protein product? My girlfriend would be ashamed that I don't know what proteomics is.

Did you have any particular question regarding serotonin and depression? In general, serotonin levels, and many of the precursors for the generation of the particular neurotransmitter, tend to be lower in people with depression. That's the reason behind the use of SSRIs (selective serotonin reuptake inhibitors) in people with depression. By blocking the reuptake of serotonin in the synaptic cleft, you increase the amount of time the neurotransmitter remains active at the synapse, and compensates for any deficiency in serotonin there might be. There's a ton of neuroscience/neurology research going about about this. Is there something specific you wanted to know? There's a good article reviewing the pathology between serotonin and depression that might be useful:

Genetics gives you what is possible, proteomics gives you what actually is. Just because a particular gene exists doesn't mean it's being expressed, and even if it's being expressed, it doesn't tell you anything about how much it's being expressed. Proteomics has the potential to quantify the proteins in a cell (and proteins are the vast majority of the molecules that do something). For example, let's say you find an allele gene that is involved in tumorgenesis. Just because the gene exists in your given tissue doesn't mean that tissue is cancerous. But if you find the protein product of the gene being expressed, and that protein is a biomarker of cancer, then you might be able to say something about whether a tumor is present or not.

So I'm currently a PhD student in Medical Engineering with a focus in Neuroscience/Neuroengineering, and I would say that you shouldn't worry too much about the classes. You are clearly very motivated and know what you want to do. In general (I can't speak to specifics of programs besides my own), I would say that grad programs, especially PhD programs, tend to care most about your research interests, your background in said interest, and the letters of recommendation you get from people you've done research with. The minor details of the coursework, while they can play a factor in admissions, generally come second to research related qualifications. With regards to your interest in cellular/molecular neuroscience, I would agree with one of the previous posters in saying that the most important thing for you to do is to get research in a molecular/cellular neuroscience lab if possible. Is there any way to get a lab tech position while you're applying to programs? But even if you don't have the most experience this particular field, you've done quite a bit of research already, and this is already a plus. Just because you have less experience in cellular neuroscience doesn't mean you won't get into a neuroscience PhD program. They don't expect newly admitted PhD students to know exactly what they want to research. Biomedical programs might be right up your alley since they're so multidisciplinary and they'd love someone like you who has experience in several fields. With that being said, I'd love to convince you to stay in systems neuroscience (just a personal bias). It's an amazingly rewarding field, and it's harder to get lost in the alphabet soup of gene/protein names while still understanding the big picture of what your research is doing. But I'm not going to discourage you from pursuing what you like, just a plug for my own field. All areas of neuroscience are equally important to explore.

The OP has a really interesting question. While I think it's theoretically possible to duplicate someone's brain, it is unlikely to be feasible for many decades. The level of our understanding of the brain is quite low compared to many other organ systems, and getting to the technological point at which we could duplicate every neuron and synapse functionally will be very very hard. But if you did manage to duplicate the state of all neurons in someone's brain in silico and somehow managed to interface it with all the nerves that feed into and come out of it, I would expect that person would be exactly the same as they were with their "natural" brain. Then there's tons of ethical questions that come into play. If you can duplicate someone's brain, can you create life? And if you interface this artificial brain with artificial sensors and devices to allow it to communicate with the outside world, would it be a human? Would it have the same rights as a person born naturally?

That's awesome. I had originally come up with a solution that wasn't 100% accurate as well within, but it took me much longer to figure out how to do it with 100% accuracy. Well done!