Fabp7 Is Required for Normal Sleep Suppression and Anxiety-Associated Phenotype following Single-Prolonged Stress in Mice

Round 1

Reviewer 1 Report

The manuscript entitled: FABP7 is Required for Normal Sleep Suppression and Anxiety-Associated Phenotype Following Single-Prolonged Stress in Mice, is novel and interesting to the scientists working in the field.

Minor revisions is required:

• The ethical approval number should be provided as the animals were exposed to many stressors in an experiment and surgical procedures in another experiment.
• The anesthetic agent should be mentioned and full description of the surgical procedures. It will be better to provide as supplementary data the figure of the surgical operation and the equipment used
• Also the software used to record the REM and NREM should be clarified how the recording was done
• The discussion and introduction could be enriched by providing a mechanistic pathway of sleep deprivation,provided in the following reference:

  Rolipram Rescues Memory Consolidation Deficits Caused by Sleep Deprivation: Implication of the cAMP/PKA and cAMP/Epac Pathways

Author Response

We thank the reviewer for their important comments, and have addressed them accordingly:

In the methods, we have now included the following statement “WSU Institutional Animal Care and Use Committee (IACUC; ASAF# 6459 “Astrocyte Involvement in Stress Induced Sleep Alterations”).”  

The surgical procedures, anesthesia, and recording equipment are highlighted in red in the methods section of the revised manuscript. We have also added a supplemental section with more details on surgery procedures.

We have included the following reference in the edited discussion below:

40. Maher A, El Sayed N, Nafea H, Gad MZ: Rolipram rescues memory consolidation deficits caused by sleep deprivation: Implication of the cAMP/PKA and cAMP/Epac pathways. CNS Neurol Disord Drug Targets 2021.

“Here, we observed time-of-day dependent differences in pre- and post-SPS sleep stages between FABP7 KO and WT mice (Tables 1 and 2). During the dark phase, we only saw differences in NREM sleep between FABP7 KO and WT mice following the 7-day window post-SPS (Day7). However, during the light phase, differences in REM sleep were observed between FABP7 KO and WT mice during baseline and SPS but normalized by Day7. The light phase post-trauma increases in REM sleep observed in FABP7 KO mice may be relevant for testing potential treatments for PTSD and cognitive function. The phosphodiesterase-4 (PDE4) inhibitor rolipram was shown to have anxiolytic effects in mice [39].  Rolipram treatment is known to rescue cognitive deficits following REM sleep deprivation for spatial working memory [40] or for contextual fear conditioning following total sleep deprivation [40, 41]. Whether PDE4 represents a mechanistic pathway in neural or glial cells in the relationship between changes in sleep and cognitive processing [42] in our model will require more experimentation. In addition, future work disrupting sleep, or different stages of sleep (i.e. either NREM or REM) at various time-windows post-SPS will be needed to determine the role of sleep plays in cognitive processing after trauma exposure.”

Reviewer 2 Report

In the present manuscript Vanderheyden and colleagues studied the role of FABP7, an astrocyte enriched fatty acid binding protein, using the ‘Single Prolonged Stress’ (SPS) PTSD model. Authors studied the sleep/wake parameters and anxiety behavior in FABP7 KO mice. Authors report that the wake duration during the dark (active phase) phase was similar for FABP7 at baseline and immediately after SPS however, it increased significantly after 7 days compared to WT. The wake duration for FABP7 during the dark (inactive) phase was significantly higher at baseline and immediately after SPS treatment but not after 7 days. Authors also report some changes in sleep stage distributions. Authors then show that FABP7 KO mice 7 days after SPS spend significantly more time in lit area compared to WT.  Authors conclude that FABP7 modulates stress-dependent sleep disturbances and associated anxiety behavior.

The manuscript is well written however, I have a major concern about the anxiety test. Authors site Owada et al, 2006 (15) to reason that FABP7 null mice exhibit anxiety. Could authors comment on why they observe somewhat opposite effect (Fig. 3 first 2 columns) as the FABP7 null mice show slightly higher time spent in a lit arm contrary to what one would expect.

Author Response

We thank the reviewer for their important comment, and have addressed it with the following additions to the discussion:

“Previous studies showed that FABP7 KO mice exhibit increased anxiety-like behavior [15]. Here, we observed that FABP7 KO mice spend approximately the same amount of time in the lit compartment as WT mice under baseline conditions but spend significantly more time in the lit compartment following SPS. While this effect may appear to contradict findings by Owada et al. [15], it may mean that FABP7 KO mice have anxiolytic-like effects on cognitive processing following traumatic stress or have an enhanced ‘freezing-like’ behavior when placed in the lit compartment. Therefore, future studies will be important to identify the precise mechanism that FABP7 may be playing in astrocytes to affect sleep and anxiety following trauma in our model.”

Round 2

Reviewer 1 Report

The authors addressed successfully all the coments

Reviewer 2 Report

I do not have any major concerns. My questions are addressed.