Reviewer Ian Gibbins's Review

The paper by prof Miolan and his colleagues tests a novel proposal, based on their previous work, that there is a peripheral neural reflex that can operate in the absence of action potentials. This is a big claim, and requires strong evidence. Overall, along with their earlier work, the paper provides good evidence in support of their interpretation of their data. The experiments are well designed and they have covered all the most obvious alternative explanations. Most of my comments relate to aspects of the descriptions and some of the terminology used, which does not always match usual scientific english.

General points:

1. As mentioned above, I think the data provide good support for the overall interpretation. However, I think there are two experiments that need to be done, or if they have been done already, referred to explicitly.

First: how do we know that the ceramide signalling is specifically associated with the non-action potential conduction? Is it associated with any type of peripheral neuronal activity? This would be easy to test in the coeliac ganglion prep by using the splanchnic nerve inputs as an alternative pathway.

Second, but more critical: Does the ceramide signalling require intact axons? In the prep used here, it should be relatively easy to cut the nerves between the point of application of ceramide (or another stimulant for the system) and the output of the pathway. If the stimulant effect persists, it would imply some sort of paracrine signalling environment, rather than a transmission through the axons themselves. I might be wrong, but I don't think the current experiments really rule out this alternative.

2. In the title and throughout the text: I'm not sure that the "neuronal conveyance of excitation" is the best phrase. We usually talk about neuronal conduction of information or action potential conduction or conduction velocities, etc. So I suggest replacing "conveyance" with "conduction". (in my part of the english speaking world, "conveyance" usually refers to trucks or real estate!)

3. There are a few places in the results where data are "not shown". My opinion is that if you need to use the information, then the data should be provided. This is especially important iin the analysis of low and high density fractions of the membrane preparations where the composition matters to the argument. We need to know how these fractions are characterised.

N.B. These are the general comments made by the reviewer when reviewing this paper in light of which the manuscript was revised. Specific points addressed during revision of the paper are not shown.