Prolonged development of long-term potentiation at lateral entorhinal cortex synapses onto adult-born neurons

Nicholas P. Vyleta; Jason S. Snyder

doi:10.1371/journal.pone.0253642

Peer Review History

Original SubmissionMarch 17, 2021
6 May 2021 Decision Letter - Brian R Christie, Editor PONE-D-21-08869 Prolonged development of long-term potentiation at lateral entorhinal cortex synapses onto adult-born neurons PLOS ONE Dear Dr. Snyder, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. Please submit your revised manuscript by Jun 07 2021 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. Please include the following items when submitting your revised manuscript: A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'. A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'. An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'. If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter. If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: http://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols. We look forward to receiving your revised manuscript. Kind regards, Brian R Christie Academic Editor PLOS ONE Additional Editor Comments: Hi Jason, Both reviewers liked the work, but had some issues with the figures and some of the PPR data primarily. They seem to convey pretty clearly their concerns, so they should be straightforward changes to make. bri Journal Requirements: Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. If you need to cite a retracted article, indicate the article’s retracted status in the References list and also include a citation and full reference for the retraction notice. When submitting your revision, we need you to address these additional requirements. 1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf 2. We note that you have included the phrase “data not shown” in your manuscript. Unfortunately, this does not meet our data sharing requirements. PLOS does not permit references to inaccessible data. We require that authors provide all relevant data within the paper, Supporting Information files, or in an acceptable, public repository. Please add a citation to support this phrase or upload the data that corresponds with these findings to a stable repository (such as Figshare or Dryad) and provide and URLs, DOIs, or accession numbers that may be used to access these data. Or, if the data are not a core part of the research being presented in your study, we ask that you remove the phrase that refers to these data. [Note: HTML markup is below. Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Yes Reviewer #2: Yes ******** 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes Reviewer #2: Yes ****** 3. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: Yes Reviewer #2: Yes ****** 4. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes Reviewer #2: Yes ****** 5. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: In this study the authors examined long term synaptic plasticity in newly born neurons from neonates, adults 4-6 weeks and adults 8+ weeks old. They found differing amounts of long-term plasticity that positively correlated to a decrease in probability of neurotransmitter release. Overall this is an interesting study but some issues need to be addressed. Major Issues -I assume that experiments were performed under an approved animal protocol. Because this was not stated in the Methods. Please state if this is the case in the Methods. -In Figure 2 it appears from Fig2A that the amplitudes of the baseline EPSPs progressively get smaller with age. There should be a summary graph comparing baseline amplitudes for neonatal, adult 4-6 weeks and adult 8+ weeks. -For Fig 2C we have three groups. 4-6 weeks adult; 8+ weeks adult; and neonatal. These three groups should also be indicated in Figs 2B and D as circles of different shades. For example, neonatals can be grey fill circles, adult 4-6 weeks as white circles and adult 8+ weeks as black circles or whatever shows best. -For Figure 3, it would be interesting to add the paired pulse data for neonatal mice and also indicate the different ages in the correlation graphs with different shades of circles. Minor Issue -Page 3 Line 6 of Methods: Do you actually mean hemizygous or do you mean heterozygous? Reviewer #2: This is a nicely done short report investigating whether LPP synapses onto adult born neurons can express NMDAR-dependent LTP. The data appear to be of high quality and the manuscript is for the most part clearly written. The conclusions are aligned with the findings. There are some edits needed that can improve the manuscript. 1) The y axis label for all of the figures currently with the "LTP" label (e.g. Fig 1B-D) is confusing. What do the numbers, 0-10 represent? Shouldn't it be percent of baseline, or percent potentiation? As currently labeled, it is not possible to know what is being shown. 2) The single representative examples of LTP shown in Fig 1A are nice, but it would also have been nice to see the averaged LTP data plotted over time for each group as well. 3) The PPR data shown in Fig 3A is only from the "older" adult born neurons. It would be helpful to see the same data from the "younger" ones too, before and after TBS, even though LTP expression did not occur. This is sort of shown in Fig 3F with the data plotted as a ratio, but it would be helpful to also see it plotted as in Fig 3A. 4) Might be clearer to say that the magnitude of LTP rather than extent of LTP. It is difficult to know what is meant by "extent"- could be magnitude or could be how long-lasting the potentiation is (e.g. early LTP vs late, protein synthesis dependent LTP). When the authors say, "...increasingly greater capacity for LTP with age and cellular maturity" do they mean a greater magnitude of LTP, or a greater percentage of the time LTP is successfully induced and expressed? Being more specific would be helpful. Care should also be taken to make sure induction is not confused with expression when discussing LTP. For example, in the sentence, page 6 line 8, don't the authors really mean expression of LTP rather than induction of LTP? ****** 6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review?** For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: No Reviewer #2: No [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step. https://doi.org/10.1371/journal.pone.0253642.r001
Revision 1
17 May 2021 Author Response Please find our responses to each point below, in bold. Reviewer #1: In this study the authors examined long term synaptic plasticity in newly born neurons from neonates, adults 4-6 weeks and adults 8+ weeks old. They found differing amounts of long-term plasticity that positively correlated to a decrease in probability of neurotransmitter release. Overall this is an interesting study but some issues need to be addressed. Major Issues -I assume that experiments were performed under an approved animal protocol. Because this was not stated in the Methods. Please state if this is the case in the Methods. Ah, yes – we negelected to include this and have now added a statement confirming these details (first sentence of the methods section). -In Figure 2 it appears from Fig2A that the amplitudes of the baseline EPSPs progressively get smaller with age. There should be a summary graph comparing baseline amplitudes for neonatal, adult 4-6 weeks and adult 8+ weeks. This is a good observation. Indeed, baseline EPSPs did get smaller with increasing cell age. This is most likely because cell input resistance is declining with cell age (Fig. 1C), since we find that the EPSCs do not change over time. Since these data are somewhat peripheral to our main findings, we have included these graphs as supporting information (Fig. S1) and refer to them in the 2nd paragraph of the results section. -For Fig 2C we have three groups. 4-6 weeks adult; 8+ weeks adult; and neonatal. These three groups should also be indicated in Figs 2B and D as circles of different shades. For example, neonatals can be grey fill circles, adult 4-6 weeks as white circles and adult 8+ weeks as black circles or whatever shows best. This is a good idea. Here and elsewhere we have therefore changed the symbols for the 3 groups in our correlational analyses. -For Figure 3, it would be interesting to add the paired pulse data for neonatal mice and also indicate the different ages in the correlation graphs with different shades of circles. We definitely appreciate that it could be interesting to also see the group breakdown for the PPR data in Figure 3 A. However, our main objective with Fig 3A-C was to establish whether, in our hands, LPP LTP appears presynaptic, as others have found. In revising this figure we therefore began to create multiple graphs in Fig 3A for each of the 3 groups. And, while they all showed the same trend, not all were statistically significant, likely due to smaller sample sizes for the 4-6w and neonatal groups. We would therefore prefer to keep this panel simple to illustrate the main point (that, as a whole, LPP LTP at granule cell synapses, is associated with presynaptic changes). We have, however, added mention in the text of the supplementary underlying data, should readers wish to explore the different groups. Also, we have followed the other suggestion made here and changed the symbols accordingly. Minor Issue -Page 3 Line 6 of Methods: Do you actually mean hemizygous or do you mean heterozygous? Indeed we meant heterozygous and have changed the text accordingly. Reviewer #2: This is a nicely done short report investigating whether LPP synapses onto adult born neurons can express NMDAR-dependent LTP. The data appear to be of high quality and the manuscript is for the most part clearly written. The conclusions are aligned with the findings. There are some edits needed that can improve the manuscript. 1) The y axis label for all of the figures currently with the "LTP" label (e.g. Fig 1B-D) is confusing. What do the numbers, 0-10 represent? Shouldn't it be percent of baseline, or percent potentiation? As currently labeled, it is not possible to know what is being shown. By LTP we meant “fold potentiation), where 1 = no change. But since this was not clear we have changed the y-axes of all LTP graphs to “LTP (% baseline)”. 2) The single representative examples of LTP shown in Fig 1A are nice, but it would also have been nice to see the averaged LTP data plotted over time for each group as well. We certainly agree that average time course data can be a useful visualization. However in this case there is so much variability that the averaged data obscures some of the important details. In this case we wished to emphasize the variability that can occur even amongst cells of a similar age. For example the 30 day and 39 day examples are both within the 4 to 6 week group and yet one shows LTD and the other shows LTP. Combining these in one plot versus time could give a false impression of an average phenomenon—in essence it would appear that cells in the 4 to 6 week group showed no change in EPSP amplitude—when in fact most cells showed one of two distinct processes (LTD or LTP) of substantial magnitude. Of course we continue to provide the averaged data for the final LTP magnitude in figure 2C, and provide the underlying data as supplementary material should readers wish to explore the data further. 3) The PPR data shown in Fig 3A is only from the "older" adult born neurons. It would be helpful to see the same data from the "younger" ones too, before and after TBS, even though LTP expression did not occur. This is sort of shown in Fig 3F with the data plotted as a ratio, but it would be helpful to also see it plotted as in Fig 3A. This figure actually pooled data from all cells regardless of when tamoxifen was injected. We have clarified this in the figure legend, and prefer to keep the data pooled in order to make the simple point that TBS leads to changes in PPR (as discussed above in response to reviewer #1). 4) Might be clearer to say that the magnitude of LTP rather than extent of LTP. It is difficult to know what is meant by "extent"- could be magnitude or could be how long-lasting the potentiation is (e.g. early LTP vs late, protein synthesis dependent LTP). We agree and have changed “extent” to “magnitude” When the authors say, "...increasingly greater capacity for LTP with age and cellular maturity" do they mean a greater magnitude of LTP, or a greater percentage of the time LTP is successfully induced and expressed? Being more specific would be helpful. We have changed the text to clarify: “increasingly greater capacity for LTP with age and cellular maturity - both in terms of magnitude of LTP and % of cells undergoing potentiation” Care should also be taken to make sure induction is not confused with expression when discussing LTP. For example, in the sentence, page 6 line 8, don't the authors really mean expression of LTP rather than induction of LTP? To avoid any confusion about the stage of LTP we have chaned this to “during” LTP, in addition to the following changes: Page 6, line 2: removed words “induction of”—now reads: “…after LTP.” Page 6, line 48: removed word “induction”—now reads: “…upon LTP. Page 11, line 12 (Fig. 3 Legend): removed word “induction”—now reads: “…following LTP.” Attachments Attachment Submitted filename: response to reviews.pdf https://doi.org/10.1371/journal.pone.0253642.r002
10 Jun 2021 Decision Letter - Brian R Christie, Editor Prolonged development of long-term potentiation at lateral entorhinal cortex synapses onto adult-born neurons PONE-D-21-08869R1 Dear Dr. Snyder, We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements. Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication. An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, Brian R Christie Academic Editor PLOS ONE Additional Editor Comments (optional): Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation. Reviewer #1: All comments have been addressed Reviewer #2: All comments have been addressed ******** 2. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Yes Reviewer #2: Yes ****** 3. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes Reviewer #2: Yes ****** 4. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: Yes Reviewer #2: Yes ****** 5. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes Reviewer #2: Yes ****** 6. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: (No Response) Reviewer #2: (No Response) ****** 7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review?** For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: No Reviewer #2: No https://doi.org/10.1371/journal.pone.0253642.r003
Formally Accepted
11 Jun 2021 Acceptance Letter - Brian R Christie, Editor PONE-D-21-08869R1 Prolonged development of long-term potentiation at lateral entorhinal cortex synapses onto adult-born neurons Dear Dr. Snyder: I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department. If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org. If we can help with anything else, please email us at plosone@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Dr. Brian R Christie Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0253642.r004

Open letter on the publication of peer review reports

PLOS recognizes the benefits of transparency in the peer review process. Therefore, we enable the publication of all of the content of peer review and author responses alongside final, published articles. Reviewers remain anonymous, unless they choose to reveal their names.

We encourage other journals to join us in this initiative. We hope that our action inspires the community, including researchers, research funders, and research institutions, to recognize the benefits of published peer review reports for all parts of the research system.

Learn more at ASAPbio .