*4.10. Laboratory Data and Statistical Analyses*

Data were collected using the Microsoft Excel 2016 (Microsoft Corp., Redmond, WA, USA) and, when necessary, corrected for between-session variation as described previously [88]. All the statistical analyses were performed in the Statistica software version 13.5 (StatSoft Inc., Tulsa, OK, USA). According to the normality of the results, we used the nonparametric Kruskal–Wallis test followed by Mann–Whitney U test for all analyses, except the analyses of the time spent in the target quadrant for the Barnes maze task performance, for which parametric one-way analysis of variance test was utilized. Results are expressed as means ± standard error of the mean. In all comparisons, *p* < 0.05 was considered to indicate statistical significance.

**Supplementary Materials:** The following are available online at https://www.mdpi.com/article/10 .3390/ijms22126584/s1: Figure S1. Representative microphotographs of the optic tracts in wild-type (WT) and TDP-43G348C mice at 6 months after repetitive mild traumatic brain injury (rmTBI) or sham procedure (Sham), immunostained with anti-ionized calcium-binding adaptor molecule 1 (Iba1), showing different morphological forms of microglial cells; Figure S2. Fluoro-Jade C- and cresyl-violet-stained sections of the lateral geniculate nucleus (LGN) and the superior colliculus (SC) in wild-type (WT) and TDP-43G348C mice at 6 months after repetitive mild traumatic brain injury (rmTBI); Figure S3. The activity of the glial cells in the lateral geniculate nucleus (LGN) and the superior colliculus (SC) in wild-type (WT) and TDP-43G348C mice at 6 months after repetitive mild traumatic brain injury (rmTBI); Figure S4. Synaptic plasticity in the lateral geniculate nucleus (LGN) and the superior colliculus (SC) in wild-type (WT) and TDP-43G348C mice at 6 months after repetitive mild traumatic brain injury (rmTBI).

**Author Contributions:** Conceptualization, G.Ž., K.P., and J.K.; resources, G.Ž. and J.K.; investigation, K.P., J.R.B., P.D., N.G., and T.J.; formal analysis, K.P., P.D., and J.R.B.; visualization, K.P., P.D., and J.R.B.; writing—original draft preparation, G.Ž. and K.P.; writing—review and editing, J.K., P.D., J.R.B., T.J., and N.G.; project administration, G.Ž.; supervision, G.Ž.; funding acquisition, G.Ž. All authors have read and agreed to the published version of the manuscript.

**Funding:** This work was fully funded by the Croatian Science Foundation under the project number IP-2016-06-4602 to G.Ž.

**Institutional Review Board Statement:** The study was conducted according to the guidelines of the European Community Council Directive (86/609/EEC) and the Croatian laws and rules (NN 135/06; NN 37/13; NN 125/13; NN 39/17), and approved by the Faculty Ethical Committee approval, 2 March 2017 (project "Mild repetitive traumatic brain injury: a model-system to study TDP-43 mediated neuropathology and neuroinflammation").

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The data that support the findings of this study are available within the article and supplemental data or upon request from the corresponding author.

**Acknowledgments:** The authors thank Ljerka Delaˇc, Marina Jakovac, Maja Rukavina, and Tanja Mešanovi´c from the Department of Pharmacology for their much-appreciated technical assistance. The authors are grateful to Bojan Poli´c and Sali Slavi´c Stupac from the Department of Histology and Miro Samsa from the Laboratory for Mice Breeding and Engineering Rijeka, all from the Faculty of Medicine, University of Rijeka, Rijeka, Croatia, for the breeding and maintenance of mice. Preliminary results regarding chronic neurodegeneration and glial response in the optic tract of wild and transgenic TDP-43 mice were presented at the FENS 2020 Virtual Forum of Neuroscience Glasgow, UK, 11–15 July 2020, and are available at https://www.bib.irb.hr/1084542 (18 June 2021).

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