One of my interests is how the brain works and so I find this new article in Science übercool =D:
Selective erasure of a fear memory, Science, Mar 2009
The full abstract is hidden below the fold, but here is my version of the story:
The authors have first (well, in another piece of research) found which neurons were specifically activated when a memory of fear is recalled. This of course raises the possibility that “removing” (or killing) these neurons will make the memory go away. So, using a clever bit of targeted genetics, they introduced an inducible toxin into these neurons (I suppose this means creating a genetically modified animal). Then I suppose the animal (I guess a rat, the choice animal in neuronal research) was frightened to put the memory into these cells.
Of course, the ultra-cool bit is that then, when the toxin was induced and the neurons died – the whole memory of fear was completely gone and did not return. That is just so totally WOW! This is an amazing step (in my humble and possibly wrong opinion) towards knowing exactly what is going on where in the brain and then actually influencing it directly. It also brings what happens in the movie “Eternal Sunshine of the Spotless Mind” just a little bit closer (disclaimer: I do not say that that will, or should, ever be possible :-) ).
Science. 2009 Mar 13;323(5920):1492-6.
Selective erasure of a fear memory.
Han JH, Kushner SA, Yiu AP, Hsiang HL, Buch T, Waisman A, Bontempi B, Neve RL, Frankland PW, Josselyn SA.
Memories are thought to be encoded by sparsely distributed groups of neurons. However, identifying the precise neurons supporting a given memory (the memory trace) has been a long-standing challenge. We have shown previously that lateral amygdala (LA) neurons with increased cyclic adenosine monophosphate response element-binding protein (CREB) are preferentially activated by fear memory expression, which suggests that they are selectively recruited into the memory trace. We used an inducible diphtheria-toxin strategy to specifically ablate these neurons. Selectively deleting neurons overexpressing CREB (but not a similar portion of random LA neurons) after learning blocked expression of that fear memory. The resulting memory loss was robust and persistent, which suggests that the memory was permanently erased. These results establish a causal link between a specific neuronal subpopulation and memory expression, thereby identifying critical neurons within the memory trace.