It doesn't seem to claim that an individual neuron is the location of a memory, but rather that triggering a small number of specific neurons is necessary and sufficient to cause the behavior that would be consistent with the recall of a particular fearful memory in mice, when optogenetically triggered.
In other words, they labeled some neurons with an optogenetic receptor during fear conditioning. Then, thanks to the optogenetic labeling they previously did, they were able to activate this receptor (using light) in a totally different context (one that didn't normally elicit the freezing response associated with mouse fear). When they did so, the mouse exhibited the freezing response. When they ablate these neurons, there is no fear response. The conclusion is that these neurons are necessary and sufficient to encode the fear memory.
Caveat lector: my summary is based on the abstract so I am just parroting what they have concluded; I haven't read the paper's methods and results for myself. Also, this is the "near-final" version published in advance online today. It may change for final publication.
It doesn't seem to claim that an individual neuron is the location of a memory, but rather that triggering a small number of specific neurons is necessary and sufficient to cause the behavior that would be consistent with the recall of a particular fearful memory in mice, when optogenetically triggered.
In other words, they labeled some neurons with an optogenetic receptor during fear conditioning. Then, thanks to the optogenetic labeling they previously did, they were able to activate this receptor (using light) in a totally different context (one that didn't normally elicit the freezing response associated with mouse fear). When they did so, the mouse exhibited the freezing response. When they ablate these neurons, there is no fear response. The conclusion is that these neurons are necessary and sufficient to encode the fear memory.
Caveat lector: my summary is based on the abstract so I am just parroting what they have concluded; I haven't read the paper's methods and results for myself. Also, this is the "near-final" version published in advance online today. It may change for final publication.