RE: Sleeping to forget - The delete button of the archivist in the brain.
As usual, this was an amazing post to read! Thanks for putting all of this state-of-the-art research together! I liked to think about the credo of "Somehow, we need to forget to reinforce memorising new things better". Well, more or less... :)
Anyways, I however have one very real question. So far, we seem to understand better how memory works with mice and we can start playing with it. This is after all what Izawa et al. did. But how all of this can be transferred to normal mice, and further, to other beasts (including humans). Would it work strictly the same?
PS: I loved the name ‘MCH-Cre mouse’
PS2: the links at the end of the post look weird on steemstem.io but this will be fixed when I will deploy the new markdown/html converter. I just do not know when I will finish it (hopefully this week). If you want to fix it already know, it is important not to mix markdown and HTML together. You can use this piece of code for instance:
<a href="https://steemconnect.com/sign/account_witness_vote?approve=1&witness=stem.witness">
<img src="https://cdn.discordapp.com/attachments/354723995037466624/623491172400103424/Witness_Banner.jpg">
</a>
I actually wrote two answers to your question. I will call it a short answer and a long answer.
Short answer : The way this could be transferred to other beasts would be to develop small molecule drugs that can activate/deactivate certain set of neurons to achieve the goal at hand. Example from Izawa et al would be a drug that is MCH agonist. People with say PTSD sleep after taking the drug. The therapist plays triggers that turn on the memory.
Long answer:
That's the thing you know, most of our knowledge about how biological things work is based either on looking at artificial systems (like cell culture), or animal models. Memory is just one of many processes we understand this way. It is sometime scary to look up papers on drugs that we take and see how much we know about them working in animals and how little we know of them working in humans.
But, then if you were editing or playing around with humans in way we do with animals we would have serious ethical issues. So we follow this principle that most biological processes are evolutionary conserved. The closer the species is to us on evolutionary timescale, less likely it would work different. Hence drugs go from understanding mechanism in mice to testing them in mice, then primates, and finally human trials.
Coming to memories. For a change it has been working pretty well in parallel with humans. For instance, the involvement of hippocampus in making new memories came from the famous HM patient. People with hippocampal injury get what is called retrograde amnesia. That is they remember old memories but can't form new memories. (They also have problems in imagining and planning future). Following these human findings mice helped a lot in understanding how hippocampus process memories. However the fact that old memories are intact also gave us hint that after initial memory formation the hippocampus sends the memory to other slow learning brain regions like cortex. Now this is where things get really interesting.
Humans have highly developed cortex compared to mice. And I won't be surprised if there drastic differences in what happens with memories here in mice vs humans. Then consolidation of memories in humans is on time scale of decade, mice don't even live that long. Sadly, we don't have many non invasive techniques to pin point the subtle differences, so it boils down to trial and error in humans from understanding gained in mice.
Some examples of mice helping in fixing human memory problems would be in therapies that uses extinction and replacement post recall in PTSD patients. Izawa et al., study has potential to yield a drug to aid in further improvement of such therapies. Will it work in humans? Time would tell.
Also, thanks for that code. I was struggling that why usual format markdown "[!image (link) ] (link) is not working.
Thanks for both the long and short answer. I was suspecting something close to what you said, but it is good to get the confirmation. From what you said, it is thus not impossible to see tests on humans (with memory issues maybe) soon in the future. Good to know (as it seems to work so well on mice).
Have a nice week-end!
PS: usual markdown will work with v1.17... But I still need to implement the treatment of tables in there.