Comments on: Forming and recalling memories. Artificially.

By: Total Recall: une vision du futur? | Botox 4 The Brain - Blog Johann Roduit

Total Recall: une vision du futur? | Botox 4 The Brain - Blog Johann Roduit — Sun, 26 Aug 2012 06:08:08 +0000

[...] Mind of a Mouse Optogenetic stimulation of a hippocampal engram activates fear memory recall Forming and recalling memories. Artificially Does Memory Modification Threaten Our Authenticity? Print [...]

By: felicia

felicia — Mon, 25 Jun 2012 06:00:23 +0000

Hi! can you help me with my thesis? I’m handling animal’s or our pet’s memory. I want to know if you have any idea than can be of my use. Proper credits and copyright’s shall be imposed. by the way, after reading your post, a question came across my mind, if through researches, it was found out that there’s a higher probability that memories can be manipulated in some way, i wonder if in cases of loss memories – i mean like amnesias – will it be a bit of help to the family of the patient if these strats and findings be used?

By: Zejun Wang

Zejun Wang — Wed, 04 Apr 2012 03:28:34 +0000

Excellent comments! I am just thinking about if granule cells can work for different behaviors such as pattern separation and completion. One paper recently published on Cell also from Tonegawa lab said that there is a possibility that young and old granule cells might be responsible for oppositing behaviors. In fact, researchers have already found the similar results from piriform cortex, which driving the same or different ensembles of piriform cortex will induce opposite behaviors (aversive or appetitive) by using ChR2.

By: Jason Snyder

Jason Snyder — Sun, 25 Mar 2012 13:40:47 +0000

That does sound like a cool direction – and it adds a new level of specificity, by activation one memory vs another. Also adds a level of complexity because you’d have to differentially label and activate two distinct populations. But I think such an experiment will eventually be done.

By: AndrewHires

AndrewHires — Sat, 24 Mar 2012 03:25:37 +0000

What’s a ‘normal’ level of cfos expression? The relationship between neural activity, cell type, and cfos expression is poorly understood and the timescale of dox-on dox-off is long. This makes interpretation murky.

It is clearly possible to trigger a crude expression of behavioral modification (freezing) via activating a subset of neurons that were paired with a fearful stimulus. Its quite another thing to say “Our results show that memories really do reside in very specific brain cells,” Liu says, “and simply by reactivating these cells by physical means, such as light, an entire memory can be recalled.”

By: Lucas

Lucas — Sat, 24 Mar 2012 02:46:51 +0000

I think it would be quite interesting to test them on a simple t-maze task to asymptotic criterion where they must go left if they smell a neutral smell (say “wood”) or right if they smell “grass”. Find those populations for each of those memories (presumably, smelling one thing will cue the rest of the associative memory which would be distinct, possibly, from the other associative memory), and see if, by activating the reverse population, they can change the mouse’s behavior.

By: Action Potential: Fear of the Light : Action Potential

Action Potential: Fear of the Light : Action Potential — Fri, 23 Mar 2012 17:20:30 +0000

[...] Your prayers have been answered because Jason Snyder of the Functional Neurogenesis blog has written up more on the complementary paper from the Mayford group. Even more coverage from science writer Ed [...]

By: John Sakon

John Sakon — Fri, 23 Mar 2012 16:20:21 +0000

Still need to do a lot of reading before I can fully grasp how all this ties together, but my initial thought is the difference between how the DG differentiates similar and non-similar contexts can account for some of these distinct cell populations being summoned in the DG. For example Sahay et al. (http://www.nature.com/nature/journal/v472/n7344/full/nature09817.html) showed how a different context, context C, was not treated the same way by the DG as context B, a similar context, in comparison to the original context A (same idea in Nakashiba et al http://www.cell.com/abstract/S0092-8674%2812%2900157-2 with only new neurons involved). Then the overlap amongst cells is seen in the more cell (and association) rich CA3 ( http://www.abstractsonline.com/Plan/ViewAbstract.aspx?sKey=19cacc88-faab-469f-a013-34f7592d3b43&cKey=1cfee4ef-a30d-402b-8012-6fee78a34272&mKey={8334BE29-8911-4991-8C31-32B32DD5E6C8} ).

By: Jason Snyder

Jason Snyder — Fri, 23 Mar 2012 16:15:09 +0000

Hi Alix – I tried, albeit briefly, to emphasize at the beginning that understanding the neural basis of memory has HUGE implications for human health. That is indeed the primary goal of this research and a very big part of why most scientists do research. This research can help people but it cannot be done on people, except in very rare occasions where patients give us a window into the workings of their brain during medical treatment. I agree with you that, at least once we get the answers we need, we can wean ourselves off of animal research.

By: Jason Snyder

Jason Snyder — Fri, 23 Mar 2012 16:07:05 +0000

Thanks and nice to hear from you! I’ve aways enjoyed your blog, sparse as it may be.

You’re talking about Fig 2D right, the correlation between freezing and cfos expression? That was just one animal that showed such high levels of cfos, the rest were in a normal range. A bit more of a concern is that 46% of dentate granule cells were activated by the DREADDs – a very non-physiological number. Their Fig 4C does control for the possibility that any DREADD-mediated activation in context B will increase freezing though the design was a little different than their main finding in Fig 2C…