The Mystery of Memory
[Before I go back to the subject of this thread, let me, once again, try to understand the general principles which govern the creation of memories. The results will certainly be of use in the investigation of DS-cells.]

Even if there was something like a neural trace, we would still be confronted with the retrieval problem. How does the brain know how to look for a specific memory? Does it have an internal index somewhere that it can look through?
[The homunculus is nonchalantly looking at its finger nails, pretending to clean them while whistling.]
Let us go back to the idea that I had expressed very briefly in another thread: the (inter)neuron itself is the memory. (Neurons, Action Potential and the Brain)
I know, that sounds exactly like the kind of genetic memory I reproached Hubel and Wiesel to make use of in their work. In other words, a stimulus will not change the nature of what a neuron represents or refers to. The neuron does not need a neural code because itself is the code.
Let us take a sensation of red. It does not just pop up in our brain, buts need a specific photoreceptor to create it, or at least activate it. This specific photoreceptor, via its own path through all the retinal layers, will activate a specific ganglion cell, which in turn will project to the LGN, and from there to V1. 

Let us stop there for a minute before it becomes too complex for us to handle.
From the LGN, we have to assume that the same ganglion cell will project to other parts of the brain and that somehow the sensation of red will be produced. So far, just the average brain mysteries.

Let us go back to V1. Our neuron will become a specific memory of red, and not simply a sensation, through the links that will be created with other neurons. In computer terms, we would consider all neurons (and interneurons) a baby is born with as its Read only Memory (ROM), while the new connections that are made between rom-neurons will be the Random Access Memory or RAM.[The use of computer terms must be understood purely as an analogy, didactic as it were.]
 The relationship needs not of course be absolutely static, but details are at this point irrelevant.

Therefore, we could, in a way, say that visual stimuli do nothing else but activate the dormant representation carried by each neuron. Nonetheless, that would only work, however improbable, if a single neuron is activated without creating any new (ram) memory. When researchers show an animal images of bars, spots or gratings, their are certainly creating new memories, which, unsurprisingly, they can find back in the way the neurons react later on. 

Sensory neurons will therefore either be activated directly by sensory stimulation, or by their interneurons representing the (visual) experiences the brain had.
[This of course does not apply to the optic nerve and all other sensory neurons directly linked to the external or internal environment.]
This definitely sounds like a vindication of Kandel's results.
Also, it might explain some of the results that have prompted many researchers to put all their money on so-called DS-cells.