The degree of precision increased when we increased the amplitude of these fluctuations. We believe that the signals with stronger fluctuations more closely resemble the input that neurons are likely to receive under natural conditions and therefore expect that spike timing in the animal is at least as precise as it was under the conditions that we measured it. Anything in our recording that disturbed the state of the cell or changed over the course of the experiment would have tended to reduce our estimate of the true reliability. As suggestive as our findings may be, they do not themselves prove that the cortex does use using temporal codes. Experiments will have to be designed to assess precision of other steps in the signaling process.
Many people believe that synapses in the neocortex are inherently unreliable.
If this is true, then it may mitigate the importance of reliable spike generation. This would be a very exciting finding. The implication of our evidence for a precise neural mechanism is that the exact timing of spikes may very well be used by neurons to send information to each other. This suggests that researchers ought to pay careful attention in future experiments to the exact patterns of activity occurring at very brief time scales. Generally speaking, this makes for harder experiments than simply measuring and interpreting activity over a longer time scale.