A lot has happened in the neuroscience world while I was writing my term papers and suffering at the hands of my master thesis: Elon Musk, for one, launched a company aimed at merging human brain with AI, while more down-to-earth researchers showed how brain starts to obsessively clean itself due to lack of sleep, found a binge-eating flip switch and a possible reason for why adults have more cognitive control than teenagers.
Sleep is important. Sleep is good. Sooner or later we all come to this conclusion (I now long for the far-away childhood times when daytime napping was an obligation rather than a guilty pleasure). During sleep newly formed memories get consolidated and toxic byproducts of daytime neural activity are cleaned away. Unexpectedly, as researchers from Marche Polytechnic University have found out, sleep deprivation triggers the same cleaning process, which, however, is pushed to the extreme. It seems that chronic sleep loss makes the brain go from a normal moderate weekend-cleanup straight to manic spring cleaning -- and wiping out actually healthy and necessary neuronal connections.
The scientists found that in sleep deprived mice certain brain cells are way more fired up compared to their well-rested siblings. The cells in question are called astrocytes and microglia (the former prune unnecessary connections between neurons and the latter hunt around for damaged cells and cellular rubbish). Most of the astrocyte activity was found at more mature and well-used connections which probably need a bit more maintenance attention anyway -- so not that dramatic; however, increased microglial activity in chronic insomniacs is a bit more worrisome. Excessive microglial activation has been linked to Alzheimer’s and other sucky diseases; and lack of sleep has been shown to make people vulnerable to developing a dementia, so there might be a link connecting all the dots (and didn’t Trump brag about sleeping 3-4 hours? Asking for a friend). What can I say? That all-nighter is most likely not worth it, buddy.
Now let a gal sound sensationalist for a bit: scientists made mice stuff themselves fatty food by shooting lasers into their brains! Okay, now let’s sound serious again: scientists identified a brain area (called zone inserta) whose optogenetic stimulation instantly made mice binge eat animal equivalent of chips and candy (if you’re not sure what optogenetic means, check out this article). Stopping the stimulation made the animals return to the sane and normal diet, while regular week-long stimulation made them overeat all the time (eating 35% of their daily norm in just ten minutes!) and gain a lot of weight as a consequence. As zone inserta wasn’t previously connected to feeding behavior at all, this finding is helpful for further understanding and treatment of eating disorders (maybe even a switch flip for binge eating?). It also might explain why Parkinson’s patients who undergo deep brain stimulation of motor areas close to zona inserta sometimes develop binge-eating.
And just when you think Elon Musk finally has his hands full he announces a new revolutionary endeavour. This time it’s Neuralink, a venture to create a brain-computer interface (BCI) helping people with disabilities, merging brain with AI and eventually allowing consensual telepathy (Isaac Asimov sends his greetings!).
It is supposed to be done via neural lace, an ultra thin mesh which unravels in the brain after it is injected, ultimately covering the whole cortex with a collection of electrodes which record, decode and wirelessly transmit brain signals. Neuralink team hopes to simultaneously record 1 million neurons (with the current state of art being ca. 100 electrodes recording 100 neurons and brain having around 80 billions in total). When all that is up and running we should be able to have Google Autocomplete right in our heads, restore vision, have cloud-based AI computing within our brain in a way that feels like part of us and… lots of other stuff.
If it sounds like sci-fi it’s because it’s mostly still is: current BCIs often require surgery, have very slow information transfer rate and are only able of decoding simple signals such as “I wanna move my hand to the right” or “I am looking at this particular letter” (which is still great stuff of course -- patients can control prosthetic limbs with their mind and locked-in people are allowed to communicate with the world again (see here, here and here for examples). The neural lace has to overcome all these hurdles and be ultra-thin, ultra-small, biocompatible, able to unfold and cover the cortex and have a much bigger bandwidth than current devices. Moreover, we don’t yet know enough about how exactly brain computes, we don’t know how to record enough neurons etc etc blah blah -- there is a lot to work on to achieve the next great frontier.
It is a fairly big topic so for the sake of brevity I will forward you to a huge but great in-depth text on Neuralink by WaitButWhy.
Remember how you were 15 and threw a tantrum because your mum thought a face tattoo is not the best idea? Wanna know why you don’t throw such tantrums anymore (hopefully), now that you’re an adult? Researchers from University of Pennsylvania have found what might be one of the reasons for this change. It seems that age-related changes in the brain network organisation underlie the improvement in executive functions. When the brain matures it becomes increasingly segregated in distinct modular networks (e.g., visual, attentional etc) which still have good communication with each other. Basically you have specialised units which efficiently talk to each other instead of an undifferentiated mush and this makes you better at decision-making, impulse control and other good things. It also seems that the degree to which your executive functions are developed (i.e. how likely you are to throw a tantrum or make a good decision) at least in part depends on the degree these modules are present in your brain. It is interesting to consider it as another biomarker for abnormal brain development or as a risk factor for mental diseases.
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