*4.8. Statistical Analysis*

Statistical Analysis was performed using GraphPad Prism version 8.2.0 for Windows (GraphPad Software, San Diego, CA, USA). Our data were normalised with the mean of the untreated OGD group as reference. Using a Kolmogorov–Smirnov test, we concluded that the assumption of a normal distribution was not met by our data. A two-tailed Mann–Whitney test between our control and our OGD group was used to verify our OGD model caused adequate damage. We used the Kruskal–Wallis test comparing the mean of rank of each group with every other group between the 72 h data of all OGD groups and for our control groups, respectively. Dunn's test was used to correct for multiple comparisons. For all statistical analysis, a *p*-value <0.05 was considered significant. To calculate Cohen's D, a short Python script was used.

### **5. Conclusions**

The cellular mechanisms of neuronal ischaemic damage are incredibly complex and effective neuroprotection is—as desired as it might be for all professionals working in that field—still a long way down the road. The idea of only targeting one of the mechanisms, while ischemia activates a symphony of potentially harmful pathways, is probably too simplistic. Nevertheless, the role of calcium is crucial, and the interplay of different calcium channels and their respective effect on cell injury needs further research efforts. Nimodipine remains a hot topic in SAH research mainly due to its vascular effect. Based on encouraging recent findings of a possible calcium-independent effect of nimodipine on microglia [67], we suggest to additionally add a perspective of possible neuro-regeneration to the list of experimental questions, as well as further observing effects on the microvasculature.

We again want to stress that in vitro experiments using DMSO as a solvent should be evaluated critically, since the popular drug vehicle interacts with neuronal damage mechanisms.

**Author Contributions:** Conceptualization, J.O., U.L., M.C., and A.H.; methodology, J.O., B.K., L.G., U.L., and M.C.; software, J.O.; validation, J.O., U.L., and A.H.; formal analysis, J.O.; investigation, J.O.; resources, H.C. and M.C.; data curation, J.O.; writing—original draft preparation, J.O.; writing—review and editing, all.; visualization, J.O.; supervision, U.L., R.B.-D., and A.H.; project administration, U.L.; funding acquisition, H.C., U.L., and A.H. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Acknowledgments:** The authors want to thank Joachim Weis and the Institute of Neuropathology, RWTH Aachen University for their support especially regarding the use of laboratory infrastructure. In addition, we thank Tamara Fechter and Lisa Liebenstund for their support in laboratory work and maintenance. Lastly, the first author wants to thank Patrick Emonts for his tutoring in python and the help in the initial scripts used for the data analysis.

**Conflicts of Interest:** The authors declare no conflict of interest.
