Distribution and Organization of Descending Neurons in the Brain of Adult Helicoverpa armigera (Insecta)
, Guirong Wang 2, Xinming Yin 1,* and Xincheng Zhao 1,*
Round 1
Reviewer 1 Report
The manuscript by Liu et al. is a valuable contribution to a better understanding of descending brain neurons in insects. It is, aside from the fly Drosophila, only the second holometabolous species for which a comprehensive analysis of neurons descending from the brain to the thoracic ganglia has been performed. Being an important pest insect, a better understanding of motor control pathways, as provided here, is highly appreciated. A highlight of this manuscript is clearly the discovery of a sex-specific and perhaps even species-specific population of descending neurons in males that is not present in females. Having said this, I need to emphasize, however, that the manuscript needs overall improvement in language. In my specific comments I have pointed out only a fraction of instances that need to be improved in style and or grammar.
Specific comments
Line 15: “stereotypic”, not stereotypically
Line 17/18: ….candidate neurons that may correlate….
Line 20: …seem to be conserved across….
Line 21/22: …only observed in males….
Line 22: ….DNd cluster consists of species- and….
Line 24 and several other places: the term “midbrain” should be avoided throughout the manuscript as it denotes a particular part of the vertebrate brain. The corresponding term here would be “cerebrum” including proto-, deuto-, and tritocerebrum, or “central brain” which also includes the gnathal ganglion. See Ito et al. 2014, Neuron, vol 81 for terms and nomenclature.
Line 50: ..responding…
Line 69: …by compared with the genetic mark labeling [17]. Poor grammar!
Line 92: …to the plastic pipette with wax.”
Line 92: it should be plural here (scales)
Line 93: what is the “connective nerve”? Your probably mean the neck connectives. Please indicate here that both neck connectives (the right and the left one) were backfilled
Line 105: … with an anti-synapsin antibody…
Line 112: “Followed six times rinses….” Poor style
Line 119: More important than the number of pixels (1024 x 1024) is the pixel size!
Line 144: I do not see the tritocerebrum in Figure 1
Line 145: ..in which there is not much obvious labeling found.” Poor language
Line 148: …showed less or no arborizations were stained…”. There are two verbs in this sentence.
Line 156/157: …showing different neuropil regions in the brain labeled by backfilling.”
Line 165: …are located in the anterior protocerebrum…
Line 208: …ocellar nerve entering the brain…
Line 228: “bifurcate overthere.” Poor language
Line 231: The DNm cluster is located…..
Line 251: The neurites of DNm1 neurons form the medial bundle…. Unclear, do you mean “median bundle”?
Line 279/280: poor language, sentence contains two verbs.
Line 285: The DNv somata should not be described as “DNv cluster” because they do form a single cluster but are widely dispersed at the base of the brain.
Line 303: Likewise, the DNg somata do not form a single cluster, but are widely dispersed along the surface of the GNG.
Line 320: (Figure 7B, F).
Line 327: should it rather be:….observed in the brain, but may be located…?
Line 330: tegumentary nerve
Figure 9E: in my printout of this page I could not see any labeling in the ACA. I suggest enlarging the image of Figure 9E.
Line 353/354: ….backfilling in the brain…. This is misleading! The backfill was from the neck connectives and not in the brain.
Line 408-412: Poor language
Line 420/421: “In addition, neurons homologous to the DNd of H. armigera were not found in the fruit fly, cockroach, and cricket.”
Line 424: Perhaps better: “…DNd neurons are involved in male-specific olfaction.”
Line 438: what is the middle bundle? Do you mean “median bundle”?
Line 490: …have large cell bodies…”
Line 492: “…receiving the stimulation of ocellar illuminations.” Poor style
Line 506: What is the P1 neuron?
Line 509/510: perhaps better: …in controlling backward walking when the fly encouters and impassable barrier
Line 538: perhaps better:”…medial and lateral cell body rind of the GNG.”
Author Response
Please see the attachment
Author Response File: 
Author Response.pdf
Reviewer 2 Report
It is a meticulous analysis of descending neurons revealed from the neck backfilling in Helicoverpa armigera (Ha).
However, there needs to be a more fundamental understanding of the organization of CNS in insects, so I send the author to read a few papers and incorporate them into their manuscript.
What is the midbrain in an insect? It would be more appropriate to name it proto, deuto ... and trito cerebral ganglia. I would send the author to read the book of Bullock and Horridge 1965 about the organization of CNS in insects and begin the introduction as a description of the CNS of Ha. I mean by that, how brain of Ha is organized proto- deuto- trito-. The introduction needs to include how the CNS of Ha is organized: how many fused ganglia are in the tritocerebrum, for example.
Next, about descending neurons in the cockroach, I send you the citation Harrow et al.J Exp Biol., 1980 34-5, where more than one descending neuron is described. That need to be cited.
Other concerns are the Ventral/Dorsal unpaired neurons that must be labeled when you fill in the neck connectives. Check the paper Thompson & Siegler, 1991 J. Comp Neurol 305:659-675 for grasshopper
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
The revised manuscript is suitable for publication. I accept the rebuttal in the cover letter.
